21890328 has 32 divisors (see below), whose sum is σ = 54922560. Its totient is φ = 7270560.

The previous prime is 21890317. The next prime is 21890329. The reversal of 21890328 is 82309812.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21890329) 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, 5883 + ... + 8853.

It is an arithmetic number, because the mean of its divisors is an integer number (1716330).

Almost surely, 2^21890328 is an apocalyptic number.

It is an amenable number.

21890328 is an abundant number, since it is smaller than the sum of its proper divisors (33032232).

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

21890328 is a wasteful number, since it uses less digits than its factorization.

21890328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3287 (or 3283 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 33.

The square root of 21890328 is about 4678.7100786435. The cubic root of 21890328 is about 279.7375431797.

The spelling of 21890328 in words is "twenty-one million, eight hundred ninety thousand, three hundred twenty-eight".