15538869025 has 27 divisors (see below), whose sum is σ = 19533791641. Its totient is φ = 12262063040.

The previous prime is 15538868959. The next prime is 15538869029. The reversal of 15538869025 is 52096883551.

The square root of 15538869025 is 124655.

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

It can be written as a sum of positive squares in 4 ways, for example, as 3060191761 + 12478677264 = 55319^2 + 111708^2 .

It is a de Polignac number, because none of the positive numbers 2^k-15538869025 is a prime.

It is a super-2 number, since 2×15538869025² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15538869029) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 66690309 + ... + 66690541.

Almost surely, 2^15538869025 is an apocalyptic number.

15538869025 is the 124655-th square number.

15538869025 is the 62328-th centered octagonal number.

It is an amenable number.

15538869025 is a deficient number, since it is larger than the sum of its proper divisors (3994922616).

15538869025 is an frugal number, since it uses more digits than its factorization.

15538869025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 690 (or 345 counting only the distinct ones).

The product of its (nonzero) digits is 2592000, while the sum is 52.

The spelling of 15538869025 in words is "fifteen billion, five hundred thirty-eight million, eight hundred sixty-nine thousand, twenty-five".