21113756 has 6 divisors (see below), whose sum is σ = 36949080. Its totient is φ = 10556876.

The previous prime is 21113723. The next prime is 21113773. The reversal of 21113756 is 65731112.

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 as a sum of consecutive naturals, namely, 2639216 + ... + 2639223.

It is an arithmetic number, because the mean of its divisors is an integer number (6158180).

Almost surely, 2^21113756 is an apocalyptic number.

It is an amenable number.

21113756 is a deficient number, since it is larger than the sum of its proper divisors (15835324).

21113756 is a wasteful number, since it uses less digits than its factorization.

21113756 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5278443 (or 5278441 counting only the distinct ones).

The product of its digits is 1260, while the sum is 26.

The square root of 21113756 is about 4594.9707289601. The cubic root of 21113756 is about 276.3896861856.

Adding to 21113756 its reverse (65731112), we get a palindrome (86844868).

The spelling of 21113756 in words is "twenty-one million, one hundred thirteen thousand, seven hundred fifty-six".