21735124 has 24 divisors (see below), whose sum is σ = 39318048. Its totient is φ = 10506720.

The previous prime is 21735089. The next prime is 21735137. The reversal of 21735124 is 42153712.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17814 + ... + 18994.

It is an arithmetic number, because the mean of its divisors is an integer number (1638252).

Almost surely, 2^21735124 is an apocalyptic number.

It is an amenable number.

21735124 is a deficient number, since it is larger than the sum of its proper divisors (17582924).

21735124 is a wasteful number, since it uses less digits than its factorization.

21735124 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1335 (or 1333 counting only the distinct ones).

The product of its digits is 1680, while the sum is 25.

The square root of 21735124 is about 4662.0943791391. The cubic root of 21735124 is about 279.0748547666.

Adding to 21735124 its reverse (42153712), we get a palindrome (63888836).

The spelling of 21735124 in words is "twenty-one million, seven hundred thirty-five thousand, one hundred twenty-four".