18261225017640 has 640 divisors, whose sum is σ = 70947698342400. Its totient is φ = 4163546603520.

The previous prime is 18261225017593. The next prime is 18261225017647. The reversal of 18261225017640 is 4671052216281.

18261225017640 is a `hidden beast` number, since 1 + 8 + 2 + 61 + 22 + 501 + 7 + 64 + 0 = 666.

It is a super-2 number, since 2×18261225017640² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (18261225017647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 900933426 + ... + 900953694.

It is an arithmetic number, because the mean of its divisors is an integer number (110855778660).

Almost surely, 2^{18261225017640} is an apocalyptic number.

18261225017640 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 18261225017640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35473849171200).

18261225017640 is an abundant number, since it is smaller than the sum of its proper divisors (52686473324760).

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

18261225017640 is a wasteful number, since it uses less digits than its factorization.

18261225017640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21807 (or 21794 counting only the distinct ones).

The product of its (nonzero) digits is 322560, while the sum is 45.

It can be divided in two parts, 182612 and 25017640, that added together give a palindrome (25200252).

The spelling of 18261225017640 in words is "eighteen trillion, two hundred sixty-one billion, two hundred twenty-five million, seventeen thousand, six hundred forty".