687222665 has 4 divisors (see below), whose sum is σ = 824667204. Its totient is φ = 549778128.

The previous prime is 687222661. The next prime is 687222677. The reversal of 687222665 is 566222786.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 266603584 + 420619081 = 16328^2 + 20509^2 .

It is a cyclic number.

It is not a de Polignac number, because 687222665 - 2² = 687222661 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (687222661) 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, 68722262 + ... + 68722271.

It is an arithmetic number, because the mean of its divisors is an integer number (206166801).

Almost surely, 2^687222665 is an apocalyptic number.

It is an amenable number.

687222665 is a deficient number, since it is larger than the sum of its proper divisors (137444539).

687222665 is a wasteful number, since it uses less digits than its factorization.

687222665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137444538.

The product of its digits is 483840, while the sum is 44.

The square root of 687222665 is about 26214.9320998548. The cubic root of 687222665 is about 882.4683903965.

The spelling of 687222665 in words is "six hundred eighty-seven million, two hundred twenty-two thousand, six hundred sixty-five".