261287968 has 12 divisors (see below), whose sum is σ = 514410750. Its totient is φ = 130643968.

The previous prime is 261287963. The next prime is 261287989. The reversal of 261287968 is 869782162.

261287968 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 249260944 + 12027024 = 15788^2 + 3468^2 .

It is not an unprimeable number, because it can be changed into a prime (261287963) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4082593 + ... + 4082656.

Almost surely, 2^261287968 is an apocalyptic number.

It is an amenable number.

261287968 is a deficient number, since it is larger than the sum of its proper divisors (253122782).

261287968 is an equidigital number, since it uses as much as digits as its factorization.

261287968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8165259 (or 8165251 counting only the distinct ones).

The product of its digits is 580608, while the sum is 49.

The square root of 261287968 is about 16164.4043503001. The cubic root of 261287968 is about 639.3025997023.

The spelling of 261287968 in words is "two hundred sixty-one million, two hundred eighty-seven thousand, nine hundred sixty-eight".