19905091093440 has 672 divisors, whose sum is σ = 80017646432256. Its totient is φ = 4447354429440.

The previous prime is 19905091093399. The next prime is 19905091093487. The reversal of 19905091093440 is 4439019050991.

It is a happy number.

19905091093440 is a `hidden beast` number, since 1 + 9 + 9 + 0 + 509 + 1 + 0 + 93 + 4 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (672).

It is a super-2 number, since 2×19905091093440² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 95 ways as a sum of consecutive naturals, for example, 289523709 + ... + 289592451.

Almost surely, 2^{19905091093440} is an apocalyptic number.

19905091093440 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 19905091093440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40008823216128).

19905091093440 is an abundant number, since it is smaller than the sum of its proper divisors (60112555338816).

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

19905091093440 is a wasteful number, since it uses less digits than its factorization.

19905091093440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69097 (or 69084 counting only the distinct ones).

The product of its (nonzero) digits is 1574640, while the sum is 54.

The spelling of 19905091093440 in words is "nineteen trillion, nine hundred five billion, ninety-one million, ninety-three thousand, four hundred forty".