647226621 has 24 divisors (see below), whose sum is σ = 986105120. Its totient is φ = 407936736.

The previous prime is 647226617. The next prime is 647226623. The reversal of 647226621 is 126622746.

647226621 is a `hidden beast` number, since 6 + 4 + 7 + 2 + 26 + 621 = 666.

It is not a de Polignac number, because 647226621 - 2² = 647226617 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (647226623) 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, 85815 + ... + 93051.

Almost surely, 2^647226621 is an apocalyptic number.

It is an amenable number.

647226621 is a deficient number, since it is larger than the sum of its proper divisors (338878499).

647226621 is a wasteful number, since it uses less digits than its factorization.

647226621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7785 (or 7782 counting only the distinct ones).

The product of its digits is 48384, while the sum is 36.

The square root of 647226621 is about 25440.6489893635. The cubic root of 647226621 is about 865.0053441705.

The spelling of 647226621 in words is "six hundred forty-seven million, two hundred twenty-six thousand, six hundred twenty-one".