13904890561 has 9 divisors (see below), whose sum is σ = 14295340899. Its totient is φ = 13524837624.

The previous prime is 13904890553. The next prime is 13904890579. The reversal of 13904890561 is 16509840931.

The square root of 13904890561 is 117919.

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., 12442287025 + 1462603536 = 111545^2 + 38244^2 .

It is not a de Polignac number, because 13904890561 - 2³ = 13904890553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13904890501) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 4361410 + ... + 4364596.

It is an arithmetic number, because the mean of its divisors is an integer number (1588371211).

Almost surely, 2^13904890561 is an apocalyptic number.

13904890561 is the 117919-th square number.

13904890561 is the 58960-th centered octagonal number.

It is an amenable number.

13904890561 is a deficient number, since it is larger than the sum of its proper divisors (390450338).

13904890561 is an frugal number, since it uses more digits than its factorization.

13904890561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6448 (or 3224 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 46.

The spelling of 13904890561 in words is "thirteen billion, nine hundred four million, eight hundred ninety thousand, five hundred sixty-one".