21115898 has 8 divisors (see below), whose sum is σ = 32695680. Its totient is φ = 10217340.

The previous prime is 21115883. The next prime is 21115931. The reversal of 21115898 is 89851112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×21115898² = 891762296692808, which contains 22 as substring.

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 3 ways as a sum of consecutive naturals, for example, 170228 + ... + 170351.

It is an arithmetic number, because the mean of its divisors is an integer number (4086960).

Almost surely, 2^21115898 is an apocalyptic number.

21115898 is a deficient number, since it is larger than the sum of its proper divisors (11579782).

21115898 is a wasteful number, since it uses less digits than its factorization.

21115898 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 340612.

The product of its digits is 5760, while the sum is 35.

The square root of 21115898 is about 4595.2038039678. The cubic root of 21115898 is about 276.3990324887.

The spelling of 21115898 in words is "twenty-one million, one hundred fifteen thousand, eight hundred ninety-eight".