21291124 has 12 divisors (see below), whose sum is σ = 37324000. Its totient is φ = 10627128.

The previous prime is 21291119. The next prime is 21291139. The reversal of 21291124 is 42119212.

It is a super-2 number, since 2×21291124² = 906623922366752, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21291095 and 21291104.

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, 1824 + ... + 6775.

Almost surely, 2^21291124 is an apocalyptic number.

It is an amenable number.

21291124 is a deficient number, since it is larger than the sum of its proper divisors (16032876).

21291124 is a wasteful number, since it uses less digits than its factorization.

21291124 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9222 (or 9220 counting only the distinct ones).

The product of its digits is 288, while the sum is 22.

The square root of 21291124 is about 4614.2305967517. The cubic root of 21291124 is about 277.1614744894.

The spelling of 21291124 in words is "twenty-one million, two hundred ninety-one thousand, one hundred twenty-four".