20856434472 has 64 divisors (see below), whose sum is σ = 58237977600. Its totient is φ = 6915732480.

The previous prime is 20856434461. The next prime is 20856434483. The reversal of 20856434472 is 27443465802.

It is a happy number.

20856434472 is a `hidden beast` number, since 208 + 5 + 6 + 434 + 4 + 7 + 2 = 666.

It is an interprime number because it is at equal distance from previous prime (20856434461) and next prime (20856434483).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 211513 + ... + 294024.

It is an arithmetic number, because the mean of its divisors is an integer number (909968400).

Almost surely, 2^20856434472 is an apocalyptic number.

It is an amenable number.

20856434472 is an abundant number, since it is smaller than the sum of its proper divisors (37381543128).

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

20856434472 is a wasteful number, since it uses less digits than its factorization.

20856434472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 505743 (or 505733 counting only the distinct ones).

The product of its (nonzero) digits is 1290240, while the sum is 45.

The spelling of 20856434472 in words is "twenty billion, eight hundred fifty-six million, four hundred thirty-four thousand, four hundred seventy-two".