21156360935424 has 768 divisors, whose sum is σ = 67964063731200. Its totient is φ = 5815835688960.

The previous prime is 21156360935351. The next prime is 21156360935431. The reversal of 21156360935424 is 42453906365112.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (768).

It is a congruent number.

It is an unprimeable number.

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 63 ways as a sum of consecutive naturals, for example, 6272266602 + ... + 6272269974.

It is an arithmetic number, because the mean of its divisors is an integer number (88494874650).

Almost surely, 2^{21156360935424} is an apocalyptic number.

21156360935424 is a gapful number since it is divisible by the number (24) 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 21156360935424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33982031865600).

21156360935424 is an abundant number, since it is smaller than the sum of its proper divisors (46807702795776).

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

21156360935424 is a wasteful number, since it uses less digits than its factorization.

21156360935424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3503 (or 3461 counting only the distinct ones).

The product of its (nonzero) digits is 4665600, while the sum is 51.

The spelling of 21156360935424 in words is "twenty-one trillion, one hundred fifty-six billion, three hundred sixty million, nine hundred thirty-five thousand, four hundred twenty-four".