21036805693456 has 320 divisors, whose sum is σ = 48380903424000. Its totient is φ = 8676867064320.

The previous prime is 21036805693447. The next prime is 21036805693493. The reversal of 21036805693456 is 65439650863012.

It is a self number, because there is not a number n which added to its sum of digits gives 21036805693456.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 25073665485 + ... + 25073666323.

It is an arithmetic number, because the mean of its divisors is an integer number (151190323200).

Almost surely, 2^{21036805693456} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21036805693456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24190451712000).

21036805693456 is an abundant number, since it is smaller than the sum of its proper divisors (27344097730544).

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

21036805693456 is a wasteful number, since it uses less digits than its factorization.

21036805693456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1410 (or 1404 counting only the distinct ones).

The product of its (nonzero) digits is 27993600, while the sum is 58.

The spelling of 21036805693456 in words is "twenty-one trillion, thirty-six billion, eight hundred five million, six hundred ninety-three thousand, four hundred fifty-six".