646640116 has 6 divisors (see below), whose sum is σ = 1131620210. Its totient is φ = 323320056.

The previous prime is 646640087. The next prime is 646640117. The reversal of 646640116 is 611046646.

It can be written as a sum of positive squares in only one way, i.e., 645363216 + 1276900 = 25404^2 + 1130^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646640117) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80830011 + ... + 80830018.

Almost surely, 2^646640116 is an apocalyptic number.

It is an amenable number.

646640116 is a deficient number, since it is larger than the sum of its proper divisors (484980094).

646640116 is a wasteful number, since it uses less digits than its factorization.

646640116 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161660033 (or 161660031 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 34.

The square root of 646640116 is about 25429.1194499534. The cubic root of 646640116 is about 864.7439811669.

The spelling of 646640116 in words is "six hundred forty-six million, six hundred forty thousand, one hundred sixteen".