21323210388 has 12 divisors (see below), whose sum is σ = 49754157600. Its totient is φ = 7107736792.

The previous prime is 21323210387. The next prime is 21323210399. The reversal of 21323210388 is 88301232312.

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

It is a super-2 number, since 2×21323210388² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21323210387) 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, 888467088 + ... + 888467111.

It is an arithmetic number, because the mean of its divisors is an integer number (4146179800).

Almost surely, 2^21323210388 is an apocalyptic number.

It is an amenable number.

21323210388 is an abundant number, since it is smaller than the sum of its proper divisors (28430947212).

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

21323210388 is a wasteful number, since it uses less digits than its factorization.

21323210388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1776934206 (or 1776934204 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 33.

The spelling of 21323210388 in words is "twenty-one billion, three hundred twenty-three million, two hundred ten thousand, three hundred eighty-eight".