21155324 has 12 divisors (see below), whose sum is σ = 37178400. Its totient is φ = 10532928.

The previous prime is 21155287. The next prime is 21155339. The reversal of 21155324 is 42355112.

It is a self number, because there is not a number n which added to its sum of digits gives 21155324.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10109 + ... + 12020.

It is an arithmetic number, because the mean of its divisors is an integer number (3098200).

Almost surely, 2^21155324 is an apocalyptic number.

It is an amenable number.

21155324 is a deficient number, since it is larger than the sum of its proper divisors (16023076).

21155324 is a wasteful number, since it uses less digits than its factorization.

21155324 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22372 (or 22370 counting only the distinct ones).

The product of its digits is 1200, while the sum is 23.

The square root of 21155324 is about 4599.4917110481. The cubic root of 21155324 is about 276.5709492923.

The spelling of 21155324 in words is "twenty-one million, one hundred fifty-five thousand, three hundred twenty-four".