21323886 has 8 divisors (see below), whose sum is σ = 42647784. Its totient is φ = 7107960.

The previous prime is 21323881. The next prime is 21323893. The reversal of 21323886 is 68832312.

It is a sphenic number, since it is the product of 3 distinct primes.

21323886 is an admirable number.

It is a super-2 number, since 2×21323886² = 909416228281992, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21323881) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1776985 + ... + 1776996.

It is an arithmetic number, because the mean of its divisors is an integer number (5330973).

Almost surely, 2^21323886 is an apocalyptic number.

21323886 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21323886 is a wasteful number, since it uses less digits than its factorization.

21323886 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3553986.

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

The square root of 21323886 is about 4617.7793364343. The cubic root of 21323886 is about 277.3035636012.

The spelling of 21323886 in words is "twenty-one million, three hundred twenty-three thousand, eight hundred eighty-six".