21372774728256 has 336 divisors, whose sum is σ = 70713238287744. Its totient is φ = 6045489635328.

The previous prime is 21372774728191. The next prime is 21372774728267. The reversal of 21372774728256 is 65282747727312.

21372774728256 is a `hidden beast` number, since 2 + 1 + 3 + 72 + 77 + 472 + 8 + 25 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (336).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a junction number, because it is equal to n+sod(n) for n = 21372774728193 and 21372774728202.

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 47 ways as a sum of consecutive naturals, for example, 695871556 + ... + 695902268.

Almost surely, 2^{21372774728256} 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 21372774728256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35356619143872).

21372774728256 is an abundant number, since it is smaller than the sum of its proper divisors (49340463559488).

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

21372774728256 is a wasteful number, since it uses less digits than its factorization.

21372774728256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32458 (or 32445 counting only the distinct ones).

The product of its digits is 110638080, while the sum is 63.

The spelling of 21372774728256 in words is "twenty-one trillion, three hundred seventy-two billion, seven hundred seventy-four million, seven hundred twenty-eight thousand, two hundred fifty-six".