21118704 has 20 divisors (see below), whose sum is σ = 54556776. Its totient is φ = 7039552.

The previous prime is 21118663. The next prime is 21118717. The reversal of 21118704 is 40781112.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 219939 + ... + 220034.

Almost surely, 2^21118704 is an apocalyptic number.

21118704 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21118704 is an abundant number, since it is smaller than the sum of its proper divisors (33438072).

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

21118704 is a wasteful number, since it uses less digits than its factorization.

21118704 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 439984 (or 439978 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 24.

The square root of 21118704 is about 4595.5091121659. The cubic root of 21118704 is about 276.4112751022.

Adding to 21118704 its reverse (40781112), we get a palindrome (61899816).

It can be divided in two parts, 211 and 18704, that added together give a triangular number (18915 = T₁₉₄).

The spelling of 21118704 in words is "twenty-one million, one hundred eighteen thousand, seven hundred four".