671720205204 has 36 divisors (see below), whose sum is σ = 1717037611380. Its totient is φ = 221390928000.

The previous prime is 671720205197. The next prime is 671720205239. The reversal of 671720205204 is 402502027176.

It is a happy number.

671720205204 is a `hidden beast` number, since 67 + 1 + 72 + 0 + 2 + 0 + 520 + 4 = 666.

671720205204 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 53452515204 + 618267690000 = 231198^2 + 786300^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 104822047 + ... + 104828454.

It is an arithmetic number, because the mean of its divisors is an integer number (47695489205).

Almost surely, 2^671720205204 is an apocalyptic number.

It is an amenable number.

671720205204 is an abundant number, since it is smaller than the sum of its proper divisors (1045317406176).

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

671720205204 is a wasteful number, since it uses less digits than its factorization.

671720205204 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 209650600 (or 209650595 counting only the distinct ones).

The product of its (nonzero) digits is 47040, while the sum is 36.

The spelling of 671720205204 in words is "six hundred seventy-one billion, seven hundred twenty million, two hundred five thousand, two hundred four".