687653257 has 4 divisors (see below), whose sum is σ = 695938320. Its totient is φ = 679368196.

The previous prime is 687653203. The next prime is 687653261. The reversal of 687653257 is 752356786.

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 a de Polignac number, because none of the positive numbers 2^k-687653257 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 687653257.

It is not an unprimeable number, because it can be changed into a prime (687653657) 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, 4142407 + ... + 4142572.

It is an arithmetic number, because the mean of its divisors is an integer number (173984580).

Almost surely, 2^687653257 is an apocalyptic number.

It is an amenable number.

687653257 is a deficient number, since it is larger than the sum of its proper divisors (8285063).

687653257 is an equidigital number, since it uses as much as digits as its factorization.

687653257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8285062.

The product of its digits is 2116800, while the sum is 49.

The square root of 687653257 is about 26223.1435377226. The cubic root of 687653257 is about 882.6526608492.

The spelling of 687653257 in words is "six hundred eighty-seven million, six hundred fifty-three thousand, two hundred fifty-seven".