21380804 has 24 divisors (see below), whose sum is σ = 38541888. Its totient is φ = 10372320.

The previous prime is 21380789. The next prime is 21380809. The reversal of 21380804 is 40808312.

It is not an unprimeable number, because it can be changed into a prime (21380809) 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, 33569 + ... + 34199.

It is an arithmetic number, because the mean of its divisors is an integer number (1605912).

Almost surely, 2^21380804 is an apocalyptic number.

It is an amenable number.

21380804 is a deficient number, since it is larger than the sum of its proper divisors (17161084).

21380804 is a wasteful number, since it uses less digits than its factorization.

21380804 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 875 (or 873 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 26.

The square root of 21380804 is about 4623.9381483753. The cubic root of 21380804 is about 277.5500718562.

The spelling of 21380804 in words is "twenty-one million, three hundred eighty thousand, eight hundred four".