261637632 has 60 divisors (see below), whose sum is σ = 755117220. Its totient is φ = 87211008.

The previous prime is 261637609. The next prime is 261637637. The reversal of 261637632 is 236736162.

261637632 is a `hidden beast` number, since 2 + 6 + 16 + 3 + 7 + 632 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261637637) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 23782 + ... + 32997.

It is an arithmetic number, because the mean of its divisors is an integer number (12585287).

Almost surely, 2^261637632 is an apocalyptic number.

It is an amenable number.

261637632 is an abundant number, since it is smaller than the sum of its proper divisors (493479588).

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

261637632 is an equidigital number, since it uses as much as digits as its factorization.

261637632 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56803 (or 56784 counting only the distinct ones).

The product of its digits is 54432, while the sum is 36.

The square root of 261637632 is about 16175.2165982407. The cubic root of 261637632 is about 639.5876510493.

The spelling of 261637632 in words is "two hundred sixty-one million, six hundred thirty-seven thousand, six hundred thirty-two".