21123124 has 12 divisors (see below), whose sum is σ = 40326048. Its totient is φ = 9601400.

The previous prime is 21123119. The next prime is 21123133. The reversal of 21123124 is 42132112.

It is a junction number, because it is equal to n+sod(n) for n = 21123098 and 21123107.

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, 239992 + ... + 240079.

It is an arithmetic number, because the mean of its divisors is an integer number (3360504).

Almost surely, 2^21123124 is an apocalyptic number.

It is an amenable number.

21123124 is a deficient number, since it is larger than the sum of its proper divisors (19202924).

21123124 is a wasteful number, since it uses less digits than its factorization.

21123124 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 480086 (or 480084 counting only the distinct ones).

The product of its digits is 96, while the sum is 16.

The square root of 21123124 is about 4595.9899912859. The cubic root of 21123124 is about 276.4305574188.

Adding to 21123124 its reverse (42132112), we get a palindrome (63255236).

The spelling of 21123124 in words is "twenty-one million, one hundred twenty-three thousand, one hundred twenty-four".