21417008 has 40 divisors (see below), whose sum is σ = 44595360. Its totient is φ = 9927680.

The previous prime is 21416999. The next prime is 21417023. The reversal of 21417008 is 80071412.

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, 18758 + ... + 19866.

It is an arithmetic number, because the mean of its divisors is an integer number (1114884).

Almost surely, 2^21417008 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21417008, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22297680).

21417008 is an abundant number, since it is smaller than the sum of its proper divisors (23178352).

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

21417008 is a wasteful number, since it uses less digits than its factorization.

21417008 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1205 (or 1199 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 23.

The square root of 21417008 is about 4627.8513372839. The cubic root of 21417008 is about 277.7066415294.

The spelling of 21417008 in words is "twenty-one million, four hundred seventeen thousand, eight".