261654625 has 8 divisors (see below), whose sum is σ = 326545128. Its totient is φ = 209323600.

The previous prime is 261654611. The next prime is 261654641. The reversal of 261654625 is 526456162.

It can be written as a sum of positive squares in 4 ways, for example, as 51955264 + 209699361 = 7208^2 + 14481^2 .

It is a de Polignac number, because none of the positive numbers 2^k-261654625 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 16.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1046494 + ... + 1046743.

It is an arithmetic number, because the mean of its divisors is an integer number (40818141).

Almost surely, 2^261654625 is an apocalyptic number.

261654625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

261654625 is a deficient number, since it is larger than the sum of its proper divisors (64890503).

261654625 is an equidigital number, since it uses as much as digits as its factorization.

261654625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2093252 (or 2093242 counting only the distinct ones).

The product of its digits is 86400, while the sum is 37.

The square root of 261654625 is about 16175.7418686130. The cubic root of 261654625 is about 639.6014975254.

The spelling of 261654625 in words is "two hundred sixty-one million, six hundred fifty-four thousand, six hundred twenty-five".