665021660522 has 16 divisors (see below), whose sum is σ = 998471609352. Its totient is φ = 332197881600.

The previous prime is 665021660509. The next prime is 665021660581. The reversal of 665021660522 is 225066120566.

It can be written as a sum of positive squares in 4 ways, for example, as 209827208761 + 455194451761 = 458069^2 + 674681^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 665021660522.

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, 17823278 + ... + 17860550.

Almost surely, 2^665021660522 is an apocalyptic number.

665021660522 is a deficient number, since it is larger than the sum of its proper divisors (333449948830).

665021660522 is a wasteful number, since it uses less digits than its factorization.

665021660522 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45433.

The product of its (nonzero) digits is 259200, while the sum is 41.

The spelling of 665021660522 in words is "six hundred sixty-five billion, twenty-one million, six hundred sixty thousand, five hundred twenty-two".