21028650 has 24 divisors (see below), whose sum is σ = 52151424. Its totient is φ = 5607600.

The previous prime is 21028619. The next prime is 21028661. The reversal of 21028650 is 5682012.

It is a self number, because there is not a number n which added to its sum of digits gives 21028650.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 69946 + ... + 70245.

It is an arithmetic number, because the mean of its divisors is an integer number (2172976).

Almost surely, 2^21028650 is an apocalyptic number.

21028650 is an abundant number, since it is smaller than the sum of its proper divisors (31122774).

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

21028650 is a wasteful number, since it uses less digits than its factorization.

21028650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140206 (or 140201 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 24.

The square root of 21028650 is about 4585.7006007806. The cubic root of 21028650 is about 276.0178259858.

The spelling of 21028650 in words is "twenty-one million, twenty-eight thousand, six hundred fifty".