646016661 has 16 divisors (see below), whose sum is σ = 957510720. Its totient is φ = 430475760.

The previous prime is 646016641. The next prime is 646016671. The reversal of 646016661 is 166610646.

It is not a de Polignac number, because 646016661 - 2⁶ = 646016597 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646016611) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 73066 + ... + 81428.

It is an arithmetic number, because the mean of its divisors is an integer number (59844420).

Almost surely, 2^646016661 is an apocalyptic number.

It is an amenable number.

646016661 is a deficient number, since it is larger than the sum of its proper divisors (311494059).

646016661 is a wasteful number, since it uses less digits than its factorization.

646016661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11233 (or 11227 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The square root of 646016661 is about 25416.8578113031. The cubic root of 646016661 is about 864.4659788673.

The spelling of 646016661 in words is "six hundred forty-six million, sixteen thousand, six hundred sixty-one".