25121565 has 36 divisors (see below), whose sum is σ = 50657724. Its totient is φ = 11483136.

The previous prime is 25121539. The next prime is 25121581. The reversal of 25121565 is 56512152.

It can be written as a sum of positive squares in 2 ways, for example, as 13972644 + 11148921 = 3738^2 + 3339^2 .

It is not a de Polignac number, because 25121565 - 2¹⁴ = 25105181 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 3492 + ... + 7901.

It is an arithmetic number, because the mean of its divisors is an integer number (1407159).

Almost surely, 2^25121565 is an apocalyptic number.

It is an amenable number.

25121565 is an abundant number, since it is smaller than the sum of its proper divisors (25536159).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

25121565 is a wasteful number, since it uses less digits than its factorization.

25121565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11418 (or 11408 counting only the distinct ones).

The product of its digits is 3000, while the sum is 27.

The square root of 25121565 is about 5012.1417577718. The cubic root of 25121565 is about 292.8749519778.

It can be divided in two parts, 2512156 and 5, that added together give a triangular number (2512161 = T₂₂₄₁).

The spelling of 25121565 in words is "twenty-five million, one hundred twenty-one thousand, five hundred sixty-five".