21550008 has 32 divisors (see below), whose sum is σ = 54028800. Its totient is φ = 7162848.

The previous prime is 21550007. The next prime is 21550043. The reversal of 21550008 is 80005512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21550003) 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, 8985 + ... + 11127.

It is an arithmetic number, because the mean of its divisors is an integer number (1688400).

Almost surely, 2^21550008 is an apocalyptic number.

It is an amenable number.

21550008 is an abundant number, since it is smaller than the sum of its proper divisors (32478792).

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

21550008 is a wasteful number, since it uses less digits than its factorization.

21550008 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2571 (or 2567 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 21.

The square root of 21550008 is about 4642.1986170348. The cubic root of 21550008 is about 278.2803100576.

The spelling of 21550008 in words is "twenty-one million, five hundred fifty thousand, eight".