20879864163601 has 27 divisors (see below), whose sum is σ = 21400605279027. Its totient is φ = 20371700309760.

The previous prime is 20879864163593. The next prime is 20879864163617. The reversal of 20879864163601 is 10636146897802.

It is a happy number.

The square root of 20879864163601 is 4569449.

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

It can be written as a sum of positive squares in 13 ways, for example, as 19907668163601 + 972196000000 = 4461801^2 + 986000^2 .

It is not a de Polignac number, because 20879864163601 - 2³ = 20879864163593 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (61).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20879864163601.

It is not an unprimeable number, because it can be changed into a prime (20879864163671) 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, 48221395081 + ... + 48221395513.

Almost surely, 2^{20879864163601} is an apocalyptic number.

20879864163601 is the 4569449-th square number.

20879864163601 is the 2284725-th centered octagonal number.

It is an amenable number.

20879864163601 is a deficient number, since it is larger than the sum of its proper divisors (520741115426).

20879864163601 is an frugal number, since it uses more digits than its factorization.

20879864163601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1334 (or 667 counting only the distinct ones).

The product of its (nonzero) digits is 20901888, while the sum is 61.

The spelling of 20879864163601 in words is "twenty trillion, eight hundred seventy-nine billion, eight hundred sixty-four million, one hundred sixty-three thousand, six hundred one".