21323436 has 12 divisors (see below), whose sum is σ = 49754712. Its totient is φ = 7107808.

The previous prime is 21323417. The next prime is 21323441. The reversal of 21323436 is 63432312.

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

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 888465 + ... + 888488.

It is an arithmetic number, because the mean of its divisors is an integer number (4146226).

Almost surely, 2^21323436 is an apocalyptic number.

It is an amenable number.

21323436 is an abundant number, since it is smaller than the sum of its proper divisors (28431276).

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

21323436 is a wasteful number, since it uses less digits than its factorization.

21323436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1776960 (or 1776958 counting only the distinct ones).

The product of its digits is 2592, while the sum is 24.

The square root of 21323436 is about 4617.7306114584. The cubic root of 21323436 is about 277.3016129329.

Adding to 21323436 its reverse (63432312), we get a palindrome (84755748).

The spelling of 21323436 in words is "twenty-one million, three hundred twenty-three thousand, four hundred thirty-six".