669157686 has 20 divisors (see below), whose sum is σ = 1499409252. Its totient is φ = 223052508.

The previous prime is 669157667. The next prime is 669157693. The reversal of 669157686 is 686751966.

669157686 is a `hidden beast` number, since 6 + 69 + 1 + 576 + 8 + 6 = 666.

669157686 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 2065140 + ... + 2065463.

Almost surely, 2^669157686 is an apocalyptic number.

669157686 is an abundant number, since it is smaller than the sum of its proper divisors (830251566).

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

669157686 is a wasteful number, since it uses less digits than its factorization.

669157686 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4130617 (or 4130608 counting only the distinct ones).

The product of its digits is 3265920, while the sum is 54.

The square root of 669157686 is about 25868.0823796431. The cubic root of 669157686 is about 874.6671652755.

The spelling of 669157686 in words is "six hundred sixty-nine million, one hundred fifty-seven thousand, six hundred eighty-six".