646642646 has 16 divisors (see below), whose sum is σ = 1047320064. Its totient is φ = 297666624.

The previous prime is 646642621. The next prime is 646642649. The reversal of 646642646 is 646246646.

It is a junction number, because it is equal to n+sod(n) for n = 646642597 and 646642606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646642649) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22511 + ... + 42426.

It is an arithmetic number, because the mean of its divisors is an integer number (65457504).

Almost surely, 2^646642646 is an apocalyptic number.

646642646 is a deficient number, since it is larger than the sum of its proper divisors (400677418).

646642646 is a wasteful number, since it uses less digits than its factorization.

646642646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65335.

The product of its digits is 995328, while the sum is 44.

The square root of 646642646 is about 25429.1691960237. The cubic root of 646642646 is about 864.7451089449.

The spelling of 646642646 in words is "six hundred forty-six million, six hundred forty-two thousand, six hundred forty-six".