21155322 has 24 divisors (see below), whose sum is σ = 44659296. Its totient is φ = 6679944.

The previous prime is 21155287. The next prime is 21155339. The reversal of 21155322 is 22355112.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2718 + ... + 7049.

It is an arithmetic number, because the mean of its divisors is an integer number (1860804).

Almost surely, 2^21155322 is an apocalyptic number.

21155322 is an abundant number, since it is smaller than the sum of its proper divisors (23503974).

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

21155322 is a wasteful number, since it uses less digits than its factorization.

21155322 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9810 (or 9791 counting only the distinct ones).

The product of its digits is 600, while the sum is 21.

The square root of 21155322 is about 4599.4914936327. The cubic root of 21155322 is about 276.5709405768.

It can be divided in two parts, 211553 and 22, that added together give a triangular number (211575 = T₆₅₀).

The spelling of 21155322 in words is "twenty-one million, one hundred fifty-five thousand, three hundred twenty-two".