21073824 has 48 divisors (see below), whose sum is σ = 61467840. Its totient is φ = 7024320.

The previous prime is 21073799. The next prime is 21073837. The reversal of 21073824 is 42837012.

It is a tau number, because it is divible by the number of its divisors (48).

It is a Harshad number since it is a multiple of its sum of digits (27).

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, 11332 + ... + 13059.

It is an arithmetic number, because the mean of its divisors is an integer number (1280580).

Almost surely, 2^21073824 is an apocalyptic number.

21073824 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21073824 is an abundant number, since it is smaller than the sum of its proper divisors (40394016).

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

21073824 is a wasteful number, since it uses less digits than its factorization.

21073824 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24410 (or 24396 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 21073824 is about 4590.6234870658. The cubic root of 21073824 is about 276.2153329006.

The spelling of 21073824 in words is "twenty-one million, seventy-three thousand, eight hundred twenty-four".