686451666 has 64 divisors (see below), whose sum is σ = 1439907840. Its totient is φ = 218015040.

The previous prime is 686451641. The next prime is 686451691. The reversal of 686451666 is 666154686.

It is an interprime number because it is at equal distance from previous prime (686451641) and next prime (686451691).

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1792111 + ... + 1792493.

It is an arithmetic number, because the mean of its divisors is an integer number (22498560).

Almost surely, 2^686451666 is an apocalyptic number.

686451666 is an abundant number, since it is smaller than the sum of its proper divisors (753456174).

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

686451666 is a wasteful number, since it uses less digits than its factorization.

686451666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 591.

The product of its digits is 1244160, while the sum is 48.

The square root of 686451666 is about 26200.2226326419. Note that the first 3 decimals coincide. The cubic root of 686451666 is about 882.1382514758.

The spelling of 686451666 in words is "six hundred eighty-six million, four hundred fifty-one thousand, six hundred sixty-six".