686684690 has 16 divisors (see below), whose sum is σ = 1236537792. Its totient is φ = 274561584.

The previous prime is 686684659. The next prime is 686684693. The reversal of 686684690 is 96486686.

It is a super-2 number, since 2×686684690² = 943071726960792200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (686684693) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14387 + ... + 39753.

It is an arithmetic number, because the mean of its divisors is an integer number (77283612).

Almost surely, 2^686684690 is an apocalyptic number.

686684690 is a deficient number, since it is larger than the sum of its proper divisors (549853102).

686684690 is a wasteful number, since it uses less digits than its factorization.

686684690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28081.

The product of its (nonzero) digits is 2985984, while the sum is 53.

The square root of 686684690 is about 26204.6692404235. The cubic root of 686684690 is about 882.2380575455.

The spelling of 686684690 in words is "six hundred eighty-six million, six hundred eighty-four thousand, six hundred ninety".