21124238 has 24 divisors (see below), whose sum is σ = 34596120. Its totient is φ = 9646560.

The previous prime is 21124199. The next prime is 21124253. The reversal of 21124238 is 83242112.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 31628 + ... + 32288.

It is an arithmetic number, because the mean of its divisors is an integer number (1441505).

Almost surely, 2^21124238 is an apocalyptic number.

21124238 is a deficient number, since it is larger than the sum of its proper divisors (13471882).

21124238 is a wasteful number, since it uses less digits than its factorization.

21124238 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 740 (or 711 counting only the distinct ones).

The product of its digits is 768, while the sum is 23.

The square root of 21124238 is about 4596.1111822931. Note that the first 4 decimals coincide. The cubic root of 21124238 is about 276.4354168362.

The spelling of 21124238 in words is "twenty-one million, one hundred twenty-four thousand, two hundred thirty-eight".