20556378324 has 18 divisors (see below), whose sum is σ = 51961956410. Its totient is φ = 6852126096.

The previous prime is 20556378277. The next prime is 20556378371. The reversal of 20556378324 is 42387365502.

20556378324 is a `hidden beast` number, since 2 + 0 + 5 + 5 + 637 + 8 + 3 + 2 + 4 = 666.

It is an interprime number because it is at equal distance from previous prime (20556378277) and next prime (20556378371).

It can be written as a sum of positive squares in only one way, i.e., 20482761924 + 73616400 = 143118^2 + 8580^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a self number, because there is not a number n which added to its sum of digits gives 20556378324.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 285505219 + ... + 285505290.

Almost surely, 2^20556378324 is an apocalyptic number.

It is an amenable number.

20556378324 is an abundant number, since it is smaller than the sum of its proper divisors (31405578086).

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

20556378324 is a wasteful number, since it uses less digits than its factorization.

20556378324 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 571010519 (or 571010514 counting only the distinct ones).

The product of its (nonzero) digits is 1209600, while the sum is 45.

The spelling of 20556378324 in words is "twenty billion, five hundred fifty-six million, three hundred seventy-eight thousand, three hundred twenty-four".