686220372 has 18 divisors (see below), whose sum is σ = 1734612698. Its totient is φ = 228740112.

The previous prime is 686220347. The next prime is 686220391. The reversal of 686220372 is 273022686.

686220372 is a `hidden beast` number, since 68 + 6 + 220 + 372 = 666.

It can be written as a sum of positive squares in only one way, i.e., 636855696 + 49364676 = 25236^2 + 7026^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 19061677 = 686220372 / (6 + 8 + 6 + 2 + 2 + 0 + 3 + 7 + 2).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 9530803 + ... + 9530874.

Almost surely, 2^686220372 is an apocalyptic number.

It is an amenable number.

686220372 is an abundant number, since it is smaller than the sum of its proper divisors (1048392326).

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

686220372 is a wasteful number, since it uses less digits than its factorization.

686220372 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19061687 (or 19061682 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 36.

The square root of 686220372 is about 26195.8082906407. The cubic root of 686220372 is about 882.0391640406.

The spelling of 686220372 in words is "six hundred eighty-six million, two hundred twenty thousand, three hundred seventy-two".