15490540521 has 15 divisors (see below), whose sum is σ = 23141863591. Its totient is φ = 10326280248.

The previous prime is 15490540519. The next prime is 15490540537. The reversal of 15490540521 is 12504509451.

The square root of 15490540521 is 124461.

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

15490540521 is a `hidden beast` number, since 1 + 5 + 4 + 90 + 5 + 40 + 521 = 666.

It can be written as a sum of positive squares in only one way, i.e., 2343624921 + 13146915600 = 48411^2 + 114660^2 .

It is not a de Polignac number, because 15490540521 - 2¹ = 15490540519 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15490540561) by changing a digit.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 1113235 + ... + 1127063.

Almost surely, 2^15490540521 is an apocalyptic number.

15490540521 is the 124461-st square number.

15490540521 is the 62231-st centered octagonal number.

It is an amenable number.

15490540521 is a deficient number, since it is larger than the sum of its proper divisors (7651323070).

15490540521 is an frugal number, since it uses more digits than its factorization.

15490540521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27670 (or 13832 counting only the distinct ones).

The product of its (nonzero) digits is 36000, while the sum is 36.

Multiplying 15490540521 by its sum of digits (36), we get a square (557659458756 = 746766²).

The spelling of 15490540521 in words is "fifteen billion, four hundred ninety million, five hundred forty thousand, five hundred twenty-one".