20657276928 has 144 divisors (see below), whose sum is σ = 59793552000. Its totient is φ = 6870589440.

The previous prime is 20657276911. The next prime is 20657276933. The reversal of 20657276928 is 82967275602.

20657276928 is a `hidden beast` number, since 2 + 0 + 6 + 572 + 7 + 69 + 2 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a super-2 number, since 2×20657276928² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11039833 + ... + 11041703.

It is an arithmetic number, because the mean of its divisors is an integer number (415233000).

Almost surely, 2^20657276928 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 20657276928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29896776000).

20657276928 is an abundant number, since it is smaller than the sum of its proper divisors (39136275072).

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

20657276928 is a wasteful number, since it uses less digits than its factorization.

20657276928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2498 (or 2475 counting only the distinct ones).

The product of its (nonzero) digits is 5080320, while the sum is 54.

The spelling of 20657276928 in words is "twenty billion, six hundred fifty-seven million, two hundred seventy-six thousand, nine hundred twenty-eight".