21382865183656 has 16 divisors (see below), whose sum is σ = 40179841580340. Its totient is φ = 10668240762240.

The previous prime is 21382865183651. The next prime is 21382865183737. The reversal of 21382865183656 is 65638156828312.

It can be written as a sum of positive squares in 2 ways, for example, as 19724523912900 + 1658341270756 = 4441230^2 + 1287766^2 .

It is not an unprimeable number, because it can be changed into a prime (21382865183651) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2898974781 + ... + 2898982156.

Almost surely, 2^{21382865183656} is an apocalyptic number.

It is an amenable number.

21382865183656 is a deficient number, since it is larger than the sum of its proper divisors (18796976396684).

21382865183656 is a wasteful number, since it uses less digits than its factorization.

21382865183656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5797957404 (or 5797957400 counting only the distinct ones).

The product of its digits is 99532800, while the sum is 64.

The spelling of 21382865183656 in words is "twenty-one trillion, three hundred eighty-two billion, eight hundred sixty-five million, one hundred eighty-three thousand, six hundred fifty-six".