20612589731881 has 27 divisors (see below), whose sum is σ = 24393422987991. Its totient is φ = 17366897588544.

The previous prime is 20612589731873. The next prime is 20612589731947. The reversal of 20612589731881 is 18813798521602.

The square root of 20612589731881 is 4540109.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 3446350909225 + 17166238822656 = 1856435^2 + 4143216^2 .

It is not a de Polignac number, because 20612589731881 - 2³ = 20612589731873 is a prime.

It is a super-2 number, since 2×20612589731881² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20612589731081) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 1875059521 + ... + 1875070513.

Almost surely, 2^{20612589731881} is an apocalyptic number.

20612589731881 is the 4540109-th square number.

20612589731881 is the 2270055-th centered octagonal number.

It is an amenable number.

20612589731881 is a deficient number, since it is larger than the sum of its proper divisors (3780833256110).

20612589731881 is an frugal number, since it uses more digits than its factorization.

20612589731881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22118 (or 11059 counting only the distinct ones).

The product of its (nonzero) digits is 11612160, while the sum is 61.

The spelling of 20612589731881 in words is "twenty trillion, six hundred twelve billion, five hundred eighty-nine million, seven hundred thirty-one thousand, eight hundred eighty-one".