21717260928 has 384 divisors, whose sum is σ = 71661283200. Its totient is φ = 6248816640.

The previous prime is 21717260911. The next prime is 21717260933. The reversal of 21717260928 is 82906271712.

It is a happy number.

21717260928 is a `hidden beast` number, since 2 + 1 + 7 + 17 + 2 + 609 + 28 = 666.

It is a tau number, because it is divible by the number of its divisors (384).

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 78401526 + ... + 78401802.

It is an arithmetic number, because the mean of its divisors is an integer number (186617925).

Almost surely, 2^21717260928 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 21717260928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35830641600).

21717260928 is an abundant number, since it is smaller than the sum of its proper divisors (49944022272).

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

21717260928 is a wasteful number, since it uses less digits than its factorization.

21717260928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 600 (or 585 counting only the distinct ones).

The product of its (nonzero) digits is 169344, while the sum is 45.

The spelling of 21717260928 in words is "twenty-one billion, seven hundred seventeen million, two hundred sixty thousand, nine hundred twenty-eight".