687661911 has 6 divisors (see below), whose sum is σ = 993289440. Its totient is φ = 458441268.

The previous prime is 687661903. The next prime is 687661913. The reversal of 687661911 is 119166786.

It is not a de Polignac number, because 687661911 - 2³ = 687661903 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (687661913) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 38203431 + ... + 38203448.

It is an arithmetic number, because the mean of its divisors is an integer number (165548240).

Almost surely, 2^687661911 is an apocalyptic number.

687661911 is a deficient number, since it is larger than the sum of its proper divisors (305627529).

687661911 is a wasteful number, since it uses less digits than its factorization.

687661911 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76406885 (or 76406882 counting only the distinct ones).

The product of its digits is 108864, while the sum is 45.

The square root of 687661911 is about 26223.3085441178. The cubic root of 687661911 is about 882.6563635119.

The spelling of 687661911 in words is "six hundred eighty-seven million, six hundred sixty-one thousand, nine hundred eleven".