21113558 has 16 divisors (see below), whose sum is σ = 33864480. Its totient is φ = 9837696.

The previous prime is 21113549. The next prime is 21113581. The reversal of 21113558 is 85531112.

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 (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 488 + ... + 6516.

It is an arithmetic number, because the mean of its divisors is an integer number (2116530).

Almost surely, 2^21113558 is an apocalyptic number.

21113558 is a deficient number, since it is larger than the sum of its proper divisors (12750922).

21113558 is a wasteful number, since it uses less digits than its factorization.

21113558 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6151.

The product of its digits is 1200, while the sum is 26.

The square root of 21113558 is about 4594.9491836145. The cubic root of 21113558 is about 276.3888222097.

The spelling of 21113558 in words is "twenty-one million, one hundred thirteen thousand, five hundred fifty-eight".