18091105211520 has 1792 divisors, whose sum is σ = 72820871424000. Its totient is φ = 4258242109440.

The previous prime is 18091105211519. The next prime is 18091105211521. The reversal of 18091105211520 is 2511250119081.

It is a happy number.

18091105211520 is a `hidden beast` number, since 1 + 8 + 0 + 9 + 1 + 105 + 21 + 1 + 520 = 666.

It is an interprime number because it is at equal distance from previous prime (18091105211519) and next prime (18091105211521).

It is a super-2 number, since 2×18091105211520² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (18091105211521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 223 ways as a sum of consecutive naturals, for example, 43176861871 + ... + 43176862289.

It is an arithmetic number, because the mean of its divisors is an integer number (40636647000).

Almost surely, 2^{18091105211520} is an apocalyptic number.

18091105211520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18091105211520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36410435712000).

18091105211520 is an abundant number, since it is smaller than the sum of its proper divisors (54729766212480).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18091105211520 is a wasteful number, since it uses less digits than its factorization.

18091105211520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 693 (or 666 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 36.

The spelling of 18091105211520 in words is "eighteen trillion, ninety-one billion, one hundred five million, two hundred eleven thousand, five hundred twenty".