20860658618409 has 81 divisors (see below), whose sum is σ = 31632136730103. Its totient is φ = 13756410698688.

The previous prime is 20860658618381. The next prime is 20860658618467. The reversal of 20860658618409 is 90481685606802.

The square root of 20860658618409 is 4567347.

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

20860658618409 is a `hidden beast` number, since 2 + 0 + 8 + 6 + 0 + 6 + 5 + 8 + 618 + 4 + 0 + 9 = 666.

It can be written as a sum of positive squares in only one way, i.e., 367581501225 + 20493077117184 = 606285^2 + 4526928^2 .

It is a tau number, because it is divible by the number of its divisors (81).

It is not a de Polignac number, because 20860658618409 - 2⁷ = 20860658618281 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20860658638409) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 41804926842 + ... + 41804927340.

Almost surely, 2^{20860658618409} is an apocalyptic number.

20860658618409 is the 4567347-th square number.

20860658618409 is the 2283674-th centered octagonal number.

It is an amenable number.

20860658618409 is a deficient number, since it is larger than the sum of its proper divisors (10771478111694).

20860658618409 is an frugal number, since it uses more digits than its factorization.

20860658618409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1248 (or 615 counting only the distinct ones).

The product of its (nonzero) digits is 39813120, while the sum is 63.

The spelling of 20860658618409 in words is "twenty trillion, eight hundred sixty billion, six hundred fifty-eight million, six hundred eighteen thousand, four hundred nine".