21245804 has 12 divisors (see below), whose sum is σ = 37212504. Its totient is φ = 10613664.

The previous prime is 21245803. The next prime is 21245839. The reversal of 21245804 is 40854212.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21245803) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7379 + ... + 9845.

It is an arithmetic number, because the mean of its divisors is an integer number (3101042).

Almost surely, 2^21245804 is an apocalyptic number.

It is an amenable number.

21245804 is a deficient number, since it is larger than the sum of its proper divisors (15966700).

21245804 is a wasteful number, since it uses less digits than its factorization.

21245804 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4624 (or 4622 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 26.

The square root of 21245804 is about 4609.3170860769. The cubic root of 21245804 is about 276.9646807309.

The spelling of 21245804 in words is "twenty-one million, two hundred forty-five thousand, eight hundred four".