21117140 has 24 divisors (see below), whose sum is σ = 48377952. Its totient is φ = 7678880.

The previous prime is 21117137. The next prime is 21117193. The reversal of 21117140 is 4171112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 47774 + ... + 48213.

It is an arithmetic number, because the mean of its divisors is an integer number (2015748).

Almost surely, 2^21117140 is an apocalyptic number.

21117140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21117140 is an abundant number, since it is smaller than the sum of its proper divisors (27260812).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21117140 is a wasteful number, since it uses less digits than its factorization.

21117140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96007 (or 96005 counting only the distinct ones).

The product of its (nonzero) digits is 56, while the sum is 17.

The square root of 21117140 is about 4595.3389428855. The cubic root of 21117140 is about 276.4044514841.

Adding to 21117140 its reverse (4171112), we get a palindrome (25288252).

The spelling of 21117140 in words is "twenty-one million, one hundred seventeen thousand, one hundred forty".