686748731 has 4 divisors (see below), whose sum is σ = 698388600. Its totient is φ = 675108864.

The previous prime is 686748701. The next prime is 686748761. The reversal of 686748731 is 137847686.

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

It is an interprime number because it is at equal distance from previous prime (686748701) and next prime (686748761).

It is a cyclic number.

It is not a de Polignac number, because 686748731 - 2¹⁰ = 686747707 is a prime.

It is a super-2 number, since 2×686748731² = 943247639060220722, which contains 22 as substring.

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 686748731.

It is not an unprimeable number, because it can be changed into a prime (686748701) 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, 5819846 + ... + 5819963.

It is an arithmetic number, because the mean of its divisors is an integer number (174597150).

Almost surely, 2^686748731 is an apocalyptic number.

686748731 is a deficient number, since it is larger than the sum of its proper divisors (11639869).

686748731 is a wasteful number, since it uses less digits than its factorization.

686748731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11639868.

The product of its digits is 1354752, while the sum is 50.

The square root of 686748731 is about 26205.8911506554. The cubic root of 686748731 is about 882.2654828699.

The spelling of 686748731 in words is "six hundred eighty-six million, seven hundred forty-eight thousand, seven hundred thirty-one".