21641866364 has 6 divisors (see below), whose sum is σ = 37873266144. Its totient is φ = 10820933180.

The previous prime is 21641866319. The next prime is 21641866409. The reversal of 21641866364 is 46366814612.

It is an interprime number because it is at equal distance from previous prime (21641866319) and next prime (21641866409).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2705233292 + ... + 2705233299.

It is an arithmetic number, because the mean of its divisors is an integer number (6312211024).

Almost surely, 2^21641866364 is an apocalyptic number.

It is an amenable number.

21641866364 is a deficient number, since it is larger than the sum of its proper divisors (16231399780).

21641866364 is a wasteful number, since it uses less digits than its factorization.

21641866364 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5410466595 (or 5410466593 counting only the distinct ones).

The product of its digits is 995328, while the sum is 47.

The spelling of 21641866364 in words is "twenty-one billion, six hundred forty-one million, eight hundred sixty-six thousand, three hundred sixty-four".