667645504365640 has 32 divisors (see below), whose sum is σ = 1504155834027000. Its totient is φ = 266710921887744.

The previous prime is 667645504365613. The next prime is 667645504365677. The reversal of 667645504365640 is 46563405546766.

It can be written as a sum of positive squares in 4 ways, for example, as 650100782561476 + 17544721804164 = 25497074^2 + 4188642^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10852464435 + ... + 10852525954.

Almost surely, 2^{667645504365640} is an apocalyptic number.

It is an amenable number.

667645504365640 is an abundant number, since it is smaller than the sum of its proper divisors (836510329661360).

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

667645504365640 is a wasteful number, since it uses less digits than its factorization.

667645504365640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21704991169 (or 21704991165 counting only the distinct ones).

The product of its (nonzero) digits is 1306368000, while the sum is 67.

The spelling of 667645504365640 in words is "six hundred sixty-seven trillion, six hundred forty-five billion, five hundred four million, three hundred sixty-five thousand, six hundred forty".