21704808 has 32 divisors (see below), whose sum is σ = 54696960. Its totient is φ = 7176960.

The previous prime is 21704797. The next prime is 21704819. The reversal of 21704808 is 80840712.

It is an interprime number because it is at equal distance from previous prime (21704797) and next prime (21704819).

It is a Smith number, since the sum of its digits (30) 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 7 ways as a sum of consecutive naturals, for example, 513 + ... + 6608.

It is an arithmetic number, because the mean of its divisors is an integer number (1709280).

Almost surely, 2^21704808 is an apocalyptic number.

It is an amenable number.

21704808 is an abundant number, since it is smaller than the sum of its proper divisors (32992152).

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

21704808 is a wasteful number, since it uses less digits than its factorization.

21704808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7257 (or 7253 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 30.

The square root of 21704808 is about 4658.8419161848. The cubic root of 21704808 is about 278.9450438384.

The spelling of 21704808 in words is "twenty-one million, seven hundred four thousand, eight hundred eight".