646216672 has 12 divisors (see below), whose sum is σ = 1272239136. Its totient is φ = 323108320.

The previous prime is 646216667. The next prime is 646216679. The reversal of 646216672 is 276612646.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646216679) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10097104 + ... + 10097167.

It is an arithmetic number, because the mean of its divisors is an integer number (106019928).

Almost surely, 2^646216672 is an apocalyptic number.

It is an amenable number.

646216672 is a deficient number, since it is larger than the sum of its proper divisors (626022464).

646216672 is a wasteful number, since it uses less digits than its factorization.

646216672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20194281 (or 20194273 counting only the distinct ones).

The product of its digits is 145152, while the sum is 40.

The square root of 646216672 is about 25420.7921198377. The cubic root of 646216672 is about 864.5551844427. Note that the first 3 decimals are identical.

The spelling of 646216672 in words is "six hundred forty-six million, two hundred sixteen thousand, six hundred seventy-two".