261631120 has 40 divisors (see below), whose sum is σ = 611014464. Its totient is φ = 104184192.

The previous prime is 261631109. The next prime is 261631133. The reversal of 261631120 is 21136162.

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 261631091 and 261631100.

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, 10957 + ... + 25363.

Almost surely, 2^261631120 is an apocalyptic number.

261631120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261631120 is an abundant number, since it is smaller than the sum of its proper divisors (349383344).

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

261631120 is a wasteful number, since it uses less digits than its factorization.

261631120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14647 (or 14641 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 261631120 is about 16175.0153013838. The cubic root of 261631120 is about 639.5823446906.

Adding to 261631120 its reverse (21136162), we get a palindrome (282767282).

The spelling of 261631120 in words is "two hundred sixty-one million, six hundred thirty-one thousand, one hundred twenty".