625551660665 has 4 divisors (see below), whose sum is σ = 750661992804. Its totient is φ = 500441328528.

The previous prime is 625551660661. The next prime is 625551660683. The reversal of 625551660665 is 566066155526.

625551660665 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 430279585849 + 195272074816 = 655957^2 + 441896^2 .

It is a cyclic number.

It is not a de Polignac number, because 625551660665 - 2² = 625551660661 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (625551660661) 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, 62555166062 + ... + 62555166071.

It is an arithmetic number, because the mean of its divisors is an integer number (187665498201).

Almost surely, 2^625551660665 is an apocalyptic number.

It is an amenable number.

625551660665 is a deficient number, since it is larger than the sum of its proper divisors (125110332139).

625551660665 is a wasteful number, since it uses less digits than its factorization.

625551660665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125110332138.

The product of its (nonzero) digits is 9720000, while the sum is 53.

The spelling of 625551660665 in words is "six hundred twenty-five billion, five hundred fifty-one million, six hundred sixty thousand, six hundred sixty-five".