21557319696 has 160 divisors (see below), whose sum is σ = 67595673600. Its totient is φ = 6523528320.

The previous prime is 21557319631. The next prime is 21557319703. The reversal of 21557319696 is 69691375512.

21557319696 is a `hidden beast` number, since 2 + 1 + 5 + 573 + 1 + 9 + 69 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3984225 + ... + 3989631.

It is an arithmetic number, because the mean of its divisors is an integer number (422472960).

Almost surely, 2^21557319696 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 21557319696, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33797836800).

21557319696 is an abundant number, since it is smaller than the sum of its proper divisors (46038353904).

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

21557319696 is a wasteful number, since it uses less digits than its factorization.

21557319696 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6274 (or 6262 counting only the distinct ones).

The product of its digits is 3061800, while the sum is 54.

The spelling of 21557319696 in words is "twenty-one billion, five hundred fifty-seven million, three hundred nineteen thousand, six hundred ninety-six".