665637832840 has 16 divisors (see below), whose sum is σ = 1497685123980. Its totient is φ = 266255133120.

The previous prime is 665637832837. The next prime is 665637832859. The reversal of 665637832840 is 48238736566.

It can be written as a sum of positive squares in 2 ways, for example, as 639465711556 + 26172121284 = 799666^2 + 161778^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8320472871 + ... + 8320472950.

Almost surely, 2^665637832840 is an apocalyptic number.

It is an amenable number.

665637832840 is an abundant number, since it is smaller than the sum of its proper divisors (832047291140).

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

665637832840 is a wasteful number, since it uses less digits than its factorization.

665637832840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16640945832 (or 16640945828 counting only the distinct ones).

The product of its (nonzero) digits is 34836480, while the sum is 58.

The spelling of 665637832840 in words is "six hundred sixty-five billion, six hundred thirty-seven million, eight hundred thirty-two thousand, eight hundred forty".