261165125 has 32 divisors (see below), whose sum is σ = 353414880. Its totient is φ = 191539200.

The previous prime is 261165119. The next prime is 261165131. The reversal of 261165125 is 521561162.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (261165119) and next prime (261165131).

It can be written as a sum of positive squares in 16 ways, for example, as 239197156 + 21967969 = 15466^2 + 4687^2 .

It is not a de Polignac number, because 261165125 - 2⁴ = 261165109 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 280661 + ... + 281589.

It is an arithmetic number, because the mean of its divisors is an integer number (11044215).

Almost surely, 2^261165125 is an apocalyptic number.

261165125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

261165125 is a deficient number, since it is larger than the sum of its proper divisors (92249755).

261165125 is a wasteful number, since it uses less digits than its factorization.

261165125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1130 (or 1120 counting only the distinct ones).

The product of its digits is 3600, while the sum is 29.

The square root of 261165125 is about 16160.6041038075. The cubic root of 261165125 is about 639.2023958793.

The spelling of 261165125 in words is "two hundred sixty-one million, one hundred sixty-five thousand, one hundred twenty-five".