21533492 has 24 divisors (see below), whose sum is σ = 40174344. Its totient is φ = 10063872.

The previous prime is 21533471. The next prime is 21533507. The reversal of 21533492 is 29433512.

It can be written as a sum of positive squares in 4 ways, for example, as 7365796 + 14167696 = 2714^2 + 3764^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9668 + ... + 11684.

It is an arithmetic number, because the mean of its divisors is an integer number (1673931).

Almost surely, 2^21533492 is an apocalyptic number.

It is an amenable number.

21533492 is a deficient number, since it is larger than the sum of its proper divisors (18640852).

21533492 is a wasteful number, since it uses less digits than its factorization.

21533492 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2195 (or 2193 counting only the distinct ones).

The product of its digits is 6480, while the sum is 29.

The square root of 21533492 is about 4640.4193775994. The cubic root of 21533492 is about 278.2092002271.

The spelling of 21533492 in words is "twenty-one million, five hundred thirty-three thousand, four hundred ninety-two".