687573666 has 48 divisors (see below), whose sum is σ = 1606845240. Its totient is φ = 211230720.

The previous prime is 687573643. The next prime is 687573697. The reversal of 687573666 is 666375786.

687573666 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 577008441 + 110565225 = 24021^2 + 10515^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 178036 + ... + 181856.

Almost surely, 2^687573666 is an apocalyptic number.

687573666 is an abundant number, since it is smaller than the sum of its proper divisors (919271574).

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

687573666 is a wasteful number, since it uses less digits than its factorization.

687573666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4611 (or 4608 counting only the distinct ones).

The product of its digits is 7620480, while the sum is 54.

The square root of 687573666 is about 26221.6259221277. The cubic root of 687573666 is about 882.6186059348.

The spelling of 687573666 in words is "six hundred eighty-seven million, five hundred seventy-three thousand, six hundred sixty-six".