21533464 has 16 divisors (see below), whose sum is σ = 40450320. Its totient is φ = 10746720.

The previous prime is 21533459. The next prime is 21533471. The reversal of 21533464 is 46433512.

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, 2709 + ... + 7099.

It is an arithmetic number, because the mean of its divisors is an integer number (2528145).

Almost surely, 2^21533464 is an apocalyptic number.

It is an amenable number.

21533464 is a deficient number, since it is larger than the sum of its proper divisors (18916856).

21533464 is a wasteful number, since it uses less digits than its factorization.

21533464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5010 (or 5006 counting only the distinct ones).

The product of its digits is 8640, while the sum is 28.

The square root of 21533464 is about 4640.4163606297. The cubic root of 21533464 is about 278.2090796419.

Adding to 21533464 its reverse (46433512), we get a palindrome (67966976).

The spelling of 21533464 in words is "twenty-one million, five hundred thirty-three thousand, four hundred sixty-four".