261315025 has 12 divisors (see below), whose sum is σ = 324322992. Its totient is φ = 208863440.

The previous prime is 261314929. The next prime is 261315031. The reversal of 261315025 is 520513162.

It is not a de Polignac number, because 261315025 - 2⁷ = 261314897 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 28002 + ... + 36148.

It is an arithmetic number, because the mean of its divisors is an integer number (27026916).

Almost surely, 2^261315025 is an apocalyptic number.

261315025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

261315025 is a deficient number, since it is larger than the sum of its proper divisors (63007967).

261315025 is a wasteful number, since it uses less digits than its factorization.

261315025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9440 (or 9435 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 25.

The square root of 261315025 is about 16165.2412601854. The cubic root of 261315025 is about 639.3246660500.

Adding to 261315025 its reverse (520513162), we get a palindrome (781828187).

The spelling of 261315025 in words is "two hundred sixty-one million, three hundred fifteen thousand, twenty-five".