21401804 has 12 divisors (see below), whose sum is σ = 37488528. Its totient is φ = 10690800.

The previous prime is 21401801. The next prime is 21401813. The reversal of 21401804 is 40810412.

It is not an unprimeable number, because it can be changed into a prime (21401801) 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, 4274 + ... + 7814.

It is an arithmetic number, because the mean of its divisors is an integer number (3124044).

Almost surely, 2^21401804 is an apocalyptic number.

It is an amenable number.

21401804 is a deficient number, since it is larger than the sum of its proper divisors (16086724).

21401804 is a wasteful number, since it uses less digits than its factorization.

21401804 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5056 (or 5054 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 20.

The square root of 21401804 is about 4626.2083826823. The cubic root of 21401804 is about 277.6409110392.

The spelling of 21401804 in words is "twenty-one million, four hundred one thousand, eight hundred four".