646650442624221 has 24 divisors (see below), whose sum is σ = 1067491779144960. Its totient is φ = 369512692196256.

The previous prime is 646650442624201. The next prime is 646650442624237. The reversal of 646650442624221 is 122426244056646.

646650442624221 is a `hidden beast` number, since 6 + 4 + 6 + 6 + 5 + 0 + 4 + 4 + 2 + 624 + 2 + 2 + 1 = 666.

It is not a de Polignac number, because 646650442624221 - 2¹³ = 646650442616029 is a prime.

It is a super-2 number, since 2×646650442624221² (a number of 30 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646650442624201) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12887365 + ... + 38201898.

It is an arithmetic number, because the mean of its divisors is an integer number (44478824131040).

Almost surely, 2^{646650442624221} is an apocalyptic number.

It is an amenable number.

646650442624221 is a deficient number, since it is larger than the sum of its proper divisors (420841336520739).

646650442624221 is a wasteful number, since it uses less digits than its factorization.

646650442624221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51290185 (or 51290182 counting only the distinct ones).

The product of its (nonzero) digits is 26542080, while the sum is 54.

The spelling of 646650442624221 in words is "six hundred forty-six trillion, six hundred fifty billion, four hundred forty-two million, six hundred twenty-four thousand, two hundred twenty-one".