21257964000 has 1440 divisors, whose sum is σ = 98693090496. Its totient is φ = 4441651200.

The previous prime is 21257963983. The next prime is 21257964019. The reversal of 21257964000 is 46975212.

21257964000 is a `hidden beast` number, since 2 + 1 + 2 + 5 + 7 + 9 + 640 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1440).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 239 ways as a sum of consecutive naturals, for example, 206387949 + ... + 206388051.

Almost surely, 2^21257964000 is an apocalyptic number.

21257964000 is a gapful number since it is divisible by the number (20) 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 21257964000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49346545248).

21257964000 is an abundant number, since it is smaller than the sum of its proper divisors (77435126496).

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

21257964000 is a wasteful number, since it uses less digits than its factorization.

21257964000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167 (or 133 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The spelling of 21257964000 in words is "twenty-one billion, two hundred fifty-seven million, nine hundred sixty-four thousand".