21366382188 has 12 divisors (see below), whose sum is σ = 49854891800. Its totient is φ = 7122127392.

The previous prime is 21366382181. The next prime is 21366382207. The reversal of 21366382188 is 88128366312.

It is a tau number, because it is divible by the number of its divisors (12).

It is not an unprimeable number, because it can be changed into a prime (21366382181) 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, 890265913 + ... + 890265936.

Almost surely, 2^21366382188 is an apocalyptic number.

It is an amenable number.

21366382188 is an abundant number, since it is smaller than the sum of its proper divisors (28488509612).

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

21366382188 is a wasteful number, since it uses less digits than its factorization.

21366382188 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1780531856 (or 1780531854 counting only the distinct ones).

The product of its digits is 663552, while the sum is 48.

The spelling of 21366382188 in words is "twenty-one billion, three hundred sixty-six million, three hundred eighty-two thousand, one hundred eighty-eight".