646362666 has 80 divisors (see below), whose sum is σ = 1495083744. Its totient is φ = 208611936.

The previous prime is 646362637. The next prime is 646362671. The reversal of 646362666 is 666263646.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 712185 + ... + 713091.

Almost surely, 2^646362666 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 646362666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (747541872).

646362666 is an abundant number, since it is smaller than the sum of its proper divisors (848721078).

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

646362666 is a wasteful number, since it uses less digits than its factorization.

646362666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1057 (or 1048 counting only the distinct ones).

The product of its digits is 1119744, while the sum is 45.

The square root of 646362666 is about 25423.6635046958. The cubic root of 646362666 is about 864.6202866347.

The spelling of 646362666 in words is "six hundred forty-six million, three hundred sixty-two thousand, six hundred sixty-six".