21440360646 has 48 divisors (see below), whose sum is σ = 49147441200. Its totient is φ = 6736250304.

The previous prime is 21440360621. The next prime is 21440360653. The reversal of 21440360646 is 64606304412.

21440360646 is a `hidden beast` number, since 2 + 1 + 4 + 4 + 0 + 3 + 6 + 0 + 646 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 21440360646.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 91741 + ... + 226488.

It is an arithmetic number, because the mean of its divisors is an integer number (1023905025).

Almost surely, 2^21440360646 is an apocalyptic number.

21440360646 is an abundant number, since it is smaller than the sum of its proper divisors (27707080554).

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

21440360646 is a wasteful number, since it uses less digits than its factorization.

21440360646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 318453 (or 318450 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 36.

The spelling of 21440360646 in words is "twenty-one billion, four hundred forty million, three hundred sixty thousand, six hundred forty-six".