646553644 has 48 divisors (see below), whose sum is σ = 1298094336. Its totient is φ = 278907200.

The previous prime is 646553629. The next prime is 646553659. The reversal of 646553644 is 446355646.

It is an interprime number because it is at equal distance from previous prime (646553629) and next prime (646553659).

It is a super-2 number, since 2×646553644² = 836063229139357472, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 646553644.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 130134 + ... + 135010.

It is an arithmetic number, because the mean of its divisors is an integer number (27043632).

Almost surely, 2^646553644 is an apocalyptic number.

It is an amenable number.

646553644 is an abundant number, since it is smaller than the sum of its proper divisors (651540692).

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

646553644 is a wasteful number, since it uses less digits than its factorization.

646553644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5046 (or 5044 counting only the distinct ones).

The product of its digits is 1036800, while the sum is 43.

The square root of 646553644 is about 25427.4191376160. The cubic root of 646553644 is about 864.7054334631.

The spelling of 646553644 in words is "six hundred forty-six million, five hundred fifty-three thousand, six hundred forty-four".