665645338490 has 32 divisors (see below), whose sum is σ = 1309382677440. Its totient is φ = 241627427200.

The previous prime is 665645338429. The next prime is 665645338529. The reversal of 665645338490 is 94833546566.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5254916 + ... + 5380095.

It is an arithmetic number, because the mean of its divisors is an integer number (40918208670).

Almost surely, 2^665645338490 is an apocalyptic number.

665645338490 is a deficient number, since it is larger than the sum of its proper divisors (643737338950).

665645338490 is a wasteful number, since it uses less digits than its factorization.

665645338490 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10635598.

The product of its (nonzero) digits is 55987200, while the sum is 59.

The spelling of 665645338490 in words is "six hundred sixty-five billion, six hundred forty-five million, three hundred thirty-eight thousand, four hundred ninety".