20390944465 has 12 divisors (see below), whose sum is σ = 24695752284. Its totient is φ = 16163050176.

The previous prime is 20390944421. The next prime is 20390944523. The reversal of 20390944465 is 56444909302.

It can be written as a sum of positive squares in 6 ways, for example, as 3467796544 + 16923147921 = 58888^2 + 130089^2 .

It is not a de Polignac number, because 20390944465 - 2²³ = 20382555857 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 112222 + ... + 231031.

It is an arithmetic number, because the mean of its divisors is an integer number (2057979357).

Almost surely, 2^20390944465 is an apocalyptic number.

It is an amenable number.

20390944465 is a deficient number, since it is larger than the sum of its proper divisors (4304807819).

20390944465 is an equidigital number, since it uses as much as digits as its factorization.

20390944465 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 343476 (or 343367 counting only the distinct ones).

The product of its (nonzero) digits is 933120, while the sum is 46.

The spelling of 20390944465 in words is "twenty billion, three hundred ninety million, nine hundred forty-four thousand, four hundred sixty-five".