21493144 has 16 divisors (see below), whose sum is σ = 40753800. Its totient is φ = 10625472.

The previous prime is 21493141. The next prime is 21493159. The reversal of 21493144 is 44139412.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21493141) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14382 + ... + 15805.

Almost surely, 2^21493144 is an apocalyptic number.

It is an amenable number.

21493144 is a deficient number, since it is larger than the sum of its proper divisors (19260656).

21493144 is a wasteful number, since it uses less digits than its factorization.

21493144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30282 (or 30278 counting only the distinct ones).

The product of its digits is 3456, while the sum is 28.

The square root of 21493144 is about 4636.0698873076. The cubic root of 21493144 is about 278.0353283950.

The spelling of 21493144 in words is "twenty-one million, four hundred ninety-three thousand, one hundred forty-four".