688013865 has 128 divisors (see below), whose sum is σ = 1540362240. Its totient is φ = 285405120.

The previous prime is 688013861. The next prime is 688013867. The reversal of 688013865 is 568310886.

It is not a de Polignac number, because 688013865 - 2² = 688013861 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 688013865.

It is not an unprimeable number, because it can be changed into a prime (688013861) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 1257522 + ... + 1258068.

It is an arithmetic number, because the mean of its divisors is an integer number (12034080).

Almost surely, 2^688013865 is an apocalyptic number.

It is an amenable number.

688013865 is an abundant number, since it is smaller than the sum of its proper divisors (852348375).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

688013865 is a wasteful number, since it uses less digits than its factorization.

688013865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 601 (or 573 counting only the distinct ones).

The product of its (nonzero) digits is 276480, while the sum is 45.

The square root of 688013865 is about 26230.0183949611. The cubic root of 688013865 is about 882.8069226985.

The spelling of 688013865 in words is "six hundred eighty-eight million, thirteen thousand, eight hundred sixty-five".