2665431738225 has 81 divisors (see below), whose sum is σ = 4934460383307. Its totient is φ = 1375314876000.

The previous prime is 2665431738191. The next prime is 2665431738253. The reversal of 2665431738225 is 5228371345662.

The square root of 2665431738225 is 1632615.

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

2665431738225 is a `hidden beast` number, since 2 + 6 + 6 + 543 + 1 + 73 + 8 + 2 + 25 = 666.

It can be written as a sum of positive squares in only one way, i.e., 959555425761 + 1705876312464 = 979569^2 + 1306092^2 .

It is not a de Polignac number, because 2665431738225 - 2⁹ = 2665431737713 is a prime.

It is a super-2 number, since 2×2665431738225² (a number of 26 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 759164220 + ... + 759167730.

Almost surely, 2^{2665431738225} is an apocalyptic number.

2665431738225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

2665431738225 is the 1632615-th square number.

2665431738225 is the 816308-th centered octagonal number.

It is an amenable number.

2665431738225 is a deficient number, since it is larger than the sum of its proper divisors (2269028645082).

2665431738225 is an frugal number, since it uses more digits than its factorization.

2665431738225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7100 (or 3550 counting only the distinct ones).

The product of its digits is 14515200, while the sum is 54.

The spelling of 2665431738225 in words is "two trillion, six hundred sixty-five billion, four hundred thirty-one million, seven hundred thirty-eight thousand, two hundred twenty-five".