261514618225 has 81 divisors (see below), whose sum is σ = 398638576737. Its totient is φ = 169665269760.

The previous prime is 261514618213. The next prime is 261514618247. The reversal of 261514618225 is 522816415162.

The square root of 261514618225 is 511385.

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 16200452961 + 245314165264 = 127281^2 + 495292^2 .

It is not a de Polignac number, because 261514618225 - 2¹⁹ = 261514093937 is a prime.

Its product of digits (230400) is a multiple of the sum of its prime divisors (800).

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, 340070641 + ... + 340071409.

Almost surely, 2^261514618225 is an apocalyptic number.

261514618225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

261514618225 is the 511385-th square number.

261514618225 is the 255693-rd centered octagonal number.

It is an amenable number.

261514618225 is a deficient number, since it is larger than the sum of its proper divisors (137123958512).

261514618225 is an frugal number, since it uses more digits than its factorization.

261514618225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1600 (or 800 counting only the distinct ones).

The product of its digits is 230400, while the sum is 43.

The spelling of 261514618225 in words is "two hundred sixty-one billion, five hundred fourteen million, six hundred eighteen thousand, two hundred twenty-five".