261315072 has 100 divisors (see below), whose sum is σ = 780080466. Its totient is φ = 87091200.

The previous prime is 261315049. The next prime is 261315083. The reversal of 261315072 is 270513162.

It is a happy number.

261315072 is a `hidden beast` number, since 26 + 131 + 507 + 2 = 666.

It can be written as a sum of positive squares in only one way, i.e., 211527936 + 49787136 = 14544^2 + 7056^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 38322 + ... + 44622.

Almost surely, 2^261315072 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261315072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (390040233).

261315072 is an abundant number, since it is smaller than the sum of its proper divisors (518765394).

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

261315072 is an frugal number, since it uses more digits than its factorization.

261315072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6331 (or 6306 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 27.

The square root of 261315072 is about 16165.2427139217. The cubic root of 261315072 is about 639.3247043795.

The spelling of 261315072 in words is "two hundred sixty-one million, three hundred fifteen thousand, seventy-two".