625551660666 has 48 divisors (see below), whose sum is σ = 1453615619040. Its totient is φ = 193815404640.

The previous prime is 625551660661. The next prime is 625551660683. The reversal of 625551660666 is 666066155526.

625551660666 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 23 ways as a sum of consecutive naturals, for example, 17237520 + ... + 17273771.

It is an arithmetic number, because the mean of its divisors is an integer number (30283658730).

Almost surely, 2^625551660666 is an apocalyptic number.

625551660666 is an abundant number, since it is smaller than the sum of its proper divisors (828063958374).

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

625551660666 is a wasteful number, since it uses less digits than its factorization.

625551660666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34511371 (or 34511368 counting only the distinct ones).

The product of its (nonzero) digits is 11664000, while the sum is 54.

The spelling of 625551660666 in words is "six hundred twenty-five billion, five hundred fifty-one million, six hundred sixty thousand, six hundred sixty-six".