21124472 has 16 divisors (see below), whose sum is σ = 41938560. Its totient is φ = 9940864.

The previous prime is 21124469. The next prime is 21124487. The reversal of 21124472 is 27442112.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 77528 + ... + 77799.

It is an arithmetic number, because the mean of its divisors is an integer number (2621160).

Almost surely, 2^21124472 is an apocalyptic number.

It is an amenable number.

21124472 is a deficient number, since it is larger than the sum of its proper divisors (20814088).

21124472 is a wasteful number, since it uses less digits than its factorization.

21124472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155350 (or 155346 counting only the distinct ones).

The product of its digits is 896, while the sum is 23.

The square root of 21124472 is about 4596.1366385259. The cubic root of 21124472 is about 276.4364375538.

Adding to 21124472 its reverse (27442112), we get a palindrome (48566584).

The spelling of 21124472 in words is "twenty-one million, one hundred twenty-four thousand, four hundred seventy-two".