261551968 has 12 divisors (see below), whose sum is σ = 514930500. Its totient is φ = 130775968.

The previous prime is 261551959. The next prime is 261551981. The reversal of 261551968 is 869155162.

261551968 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a hoax number, since the sum of its digits (43) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4086718 + ... + 4086781.

It is an arithmetic number, because the mean of its divisors is an integer number (42910875).

Almost surely, 2^261551968 is an apocalyptic number.

It is an amenable number.

261551968 is a deficient number, since it is larger than the sum of its proper divisors (253378532).

261551968 is an equidigital number, since it uses as much as digits as its factorization.

261551968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8173509 (or 8173501 counting only the distinct ones).

The product of its digits is 129600, while the sum is 43.

The square root of 261551968 is about 16172.5683798214. The cubic root of 261551968 is about 639.5178399689.

The spelling of 261551968 in words is "two hundred sixty-one million, five hundred fifty-one thousand, nine hundred sixty-eight".