21074784 has 24 divisors (see below), whose sum is σ = 55321560. Its totient is φ = 7024896.

The previous prime is 21074737. The next prime is 21074791. The reversal of 21074784 is 48747012.

It is a tau number, because it is divible by the number of its divisors (24).

It is a hoax number, since the sum of its digits (33) coincides with the sum of the digits of its distinct prime factors.

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, 109669 + ... + 109860.

It is an arithmetic number, because the mean of its divisors is an integer number (2305065).

Almost surely, 2^21074784 is an apocalyptic number.

21074784 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21074784 is an abundant number, since it is smaller than the sum of its proper divisors (34246776).

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

21074784 is a wasteful number, since it uses less digits than its factorization.

21074784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 219542 (or 219534 counting only the distinct ones).

The product of its (nonzero) digits is 12544, while the sum is 33.

The square root of 21074784 is about 4590.7280468353. The cubic root of 21074784 is about 276.2195270878.

The spelling of 21074784 in words is "twenty-one million, seventy-four thousand, seven hundred eighty-four".