21056416 has 24 divisors (see below), whose sum is σ = 41779584. Its totient is φ = 10445760.

The previous prime is 21056401. The next prime is 21056437. The reversal of 21056416 is 61465012.

It is a Smith number, since the sum of its digits (25) coincides with the sum of the digits of its prime factors.

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, 1681 + ... + 6703.

It is an arithmetic number, because the mean of its divisors is an integer number (1740816).

Almost surely, 2^21056416 is an apocalyptic number.

It is an amenable number.

21056416 is a deficient number, since it is larger than the sum of its proper divisors (20723168).

21056416 is a wasteful number, since it uses less digits than its factorization.

21056416 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5164 (or 5156 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 21056416 is about 4588.7270566030. The cubic root of 21056416 is about 276.1392561983.

The spelling of 21056416 in words is "twenty-one million, fifty-six thousand, four hundred sixteen".