21688002 has 24 divisors (see below), whose sum is σ = 53703936. Its totient is φ = 6196536.

The previous prime is 21687997. The next prime is 21688013. The reversal of 21688002 is 20088612.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 85938 + ... + 86189.

It is an arithmetic number, because the mean of its divisors is an integer number (2237664).

Almost surely, 2^21688002 is an apocalyptic number.

21688002 is an abundant number, since it is smaller than the sum of its proper divisors (32015934).

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

21688002 is a wasteful number, since it uses less digits than its factorization.

21688002 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 172142 (or 172139 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The square root of 21688002 is about 4657.0378997814. The cubic root of 21688002 is about 278.8730296732.

The spelling of 21688002 in words is "twenty-one million, six hundred eighty-eight thousand, two".