21117848 has 16 divisors (see below), whose sum is σ = 39750480. Its totient is φ = 10517728.

The previous prime is 21117847. The next prime is 21117869. The reversal of 21117848 is 84871112.

It is a super-2 number, since 2×21117848² = 891927008302208, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21117847) by changing a digit.

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, 2915 + ... + 7122.

It is an arithmetic number, because the mean of its divisors is an integer number (2484405).

Almost surely, 2^21117848 is an apocalyptic number.

It is an amenable number.

21117848 is a deficient number, since it is larger than the sum of its proper divisors (18632632).

21117848 is a wasteful number, since it uses less digits than its factorization.

21117848 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10306 (or 10302 counting only the distinct ones).

The product of its digits is 3584, while the sum is 32.

The square root of 21117848 is about 4595.4159768186. The cubic root of 21117848 is about 276.4075404783.

The spelling of 21117848 in words is "twenty-one million, one hundred seventeen thousand, eight hundred forty-eight".