21086744 has 32 divisors (see below), whose sum is σ = 46411680. Its totient is φ = 8792064.

The previous prime is 21086743. The next prime is 21086753. The reversal of 21086744 is 44768012.

It is a self number, because there is not a number n which added to its sum of digits gives 21086744.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21086743) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3017 + ... + 7160.

It is an arithmetic number, because the mean of its divisors is an integer number (1450365).

Almost surely, 2^21086744 is an apocalyptic number.

It is an amenable number.

21086744 is an abundant number, since it is smaller than the sum of its proper divisors (25324936).

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

21086744 is a wasteful number, since it uses less digits than its factorization.

21086744 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10227 (or 10223 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 32.

The square root of 21086744 is about 4592.0304877037. The cubic root of 21086744 is about 276.2717689963.

The spelling of 21086744 in words is "twenty-one million, eighty-six thousand, seven hundred forty-four".