261556425 has 96 divisors (see below), whose sum is σ = 530799360. Its totient is φ = 125452800.

The previous prime is 261556397. The next prime is 261556433. The reversal of 261556425 is 524655162.

261556425 is a `hidden beast` number, since 2 + 6 + 1 + 5 + 5 + 642 + 5 = 666.

261556425 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 261556425 - 2⁹ = 261555913 is a prime.

Its product of digits (72000) is a multiple of the sum of its prime factors (800).

It is a self number, because there is not a number n which added to its sum of digits gives 261556425.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 359412 + ... + 360138.

It is an arithmetic number, because the mean of its divisors is an integer number (5529160).

Almost surely, 2^261556425 is an apocalyptic number.

261556425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

261556425 is an abundant number, since it is smaller than the sum of its proper divisors (269242935).

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

261556425 is a wasteful number, since it uses less digits than its factorization.

261556425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 800 (or 789 counting only the distinct ones).

The product of its digits is 72000, while the sum is 36.

The square root of 261556425 is about 16172.7061742925. The cubic root of 261556425 is about 639.5214725355.

The spelling of 261556425 in words is "two hundred sixty-one million, five hundred fifty-six thousand, four hundred twenty-five".