665169402557 has 4 divisors (see below), whose sum is σ = 725639348256. Its totient is φ = 604699456860.

The previous prime is 665169402553. The next prime is 665169402581. The reversal of 665169402557 is 755204961566.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 665169402557 - 2² = 665169402553 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665169402553) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30234972833 + ... + 30234972854.

It is an arithmetic number, because the mean of its divisors is an integer number (181409837064).

Almost surely, 2^665169402557 is an apocalyptic number.

It is an amenable number.

665169402557 is a deficient number, since it is larger than the sum of its proper divisors (60469945699).

665169402557 is a wasteful number, since it uses less digits than its factorization.

665169402557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60469945698.

The product of its (nonzero) digits is 13608000, while the sum is 56.

The spelling of 665169402557 in words is "six hundred sixty-five billion, one hundred sixty-nine million, four hundred two thousand, five hundred fifty-seven".