20516722656 has 48 divisors (see below), whose sum is σ = 53936591184. Its totient is φ = 6828724224.

The previous prime is 20516722651. The next prime is 20516722661. The reversal of 20516722656 is 65622761502.

It is an interprime number because it is at equal distance from previous prime (20516722651) and next prime (20516722661).

It is a tau number, because it is divible by the number of its divisors (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20516722651) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 94171 + ... + 223386.

It is an arithmetic number, because the mean of its divisors is an integer number (1123678983).

Almost surely, 2^20516722656 is an apocalyptic number.

It is an amenable number.

20516722656 is an abundant number, since it is smaller than the sum of its proper divisors (33419868528).

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

20516722656 is a wasteful number, since it uses less digits than its factorization.

20516722656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 318243 (or 318235 counting only the distinct ones).

The product of its (nonzero) digits is 302400, while the sum is 42.

The spelling of 20516722656 in words is "twenty billion, five hundred sixteen million, seven hundred twenty-two thousand, six hundred fifty-six".