687235261 has 4 divisors (see below), whose sum is σ = 693907552. Its totient is φ = 680562972.

The previous prime is 687235247. The next prime is 687235279. The reversal of 687235261 is 162532786.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 687235261 - 2²⁵ = 653680829 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (687235231) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3335991 + ... + 3336196.

It is an arithmetic number, because the mean of its divisors is an integer number (173476888).

Almost surely, 2^687235261 is an apocalyptic number.

It is an amenable number.

687235261 is a deficient number, since it is larger than the sum of its proper divisors (6672291).

687235261 is a wasteful number, since it uses less digits than its factorization.

687235261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6672290.

The product of its digits is 120960, while the sum is 40.

The square root of 687235261 is about 26215.1723435113. The cubic root of 687235261 is about 882.4737819067.

It can be divided in two parts, 68723 and 5261, that added together give a square (73984 = 272²).

The spelling of 687235261 in words is "six hundred eighty-seven million, two hundred thirty-five thousand, two hundred sixty-one".