15664299574225 has 9 divisors (see below), whose sum is σ = 19423756010523. Its totient is φ = 12531423828120.

The previous prime is 15664299574207. The next prime is 15664299574237. The reversal of 15664299574225 is 52247599246651.

The square root of 15664299574225 is 3957815.

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., 5639147846721 + 10025151727504 = 2374689^2 + 3166252^2 .

It is not a de Polignac number, because 15664299574225 - 2¹⁹ = 15664299049937 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 19393294 + ... + 20184856.

Almost surely, 2^{15664299574225} is an apocalyptic number.

15664299574225 is the 3957815-th square number.

15664299574225 is the 1978908-th centered octagonal number.

It is an amenable number.

15664299574225 is a deficient number, since it is larger than the sum of its proper divisors (3759456436298).

15664299574225 is an frugal number, since it uses more digits than its factorization.

15664299574225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1583136 (or 791568 counting only the distinct ones).

The product of its digits is 326592000, while the sum is 67.

The spelling of 15664299574225 in words is "fifteen trillion, six hundred sixty-four billion, two hundred ninety-nine million, five hundred seventy-four thousand, two hundred twenty-five".