20556312321438 has 24 divisors (see below), whose sum is σ = 46188257315928. Its totient is φ = 6852104106984.

The previous prime is 20556312321437. The next prime is 20556312321487. The reversal of 20556312321438 is 83412321365502.

20556312321438 is a `hidden beast` number, since 2 + 0 + 5 + 5 + 6 + 312 + 321 + 4 + 3 + 8 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 20556312321393 and 20556312321402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20556312321437) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 21148468981 + ... + 21148469952.

It is an arithmetic number, because the mean of its divisors is an integer number (1924510721497).

Almost surely, 2^{20556312321438} is an apocalyptic number.

20556312321438 is an abundant number, since it is smaller than the sum of its proper divisors (25631944994490).

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

20556312321438 is an equidigital number, since it uses as much as digits as its factorization.

20556312321438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42296938950 (or 42296938938 counting only the distinct ones).

The product of its (nonzero) digits is 1036800, while the sum is 45.

The spelling of 20556312321438 in words is "twenty trillion, five hundred fifty-six billion, three hundred twelve million, three hundred twenty-one thousand, four hundred thirty-eight".