21090328 has 32 divisors (see below), whose sum is σ = 45540000. Its totient is φ = 8969472.

The previous prime is 21090299. The next prime is 21090341. The reversal of 21090328 is 82309012.

It is a congruent number.

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, 6298 + ... + 9046.

It is an arithmetic number, because the mean of its divisors is an integer number (1423125).

Almost surely, 2^21090328 is an apocalyptic number.

21090328 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21090328 is an abundant number, since it is smaller than the sum of its proper divisors (24449672).

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

21090328 is a wasteful number, since it uses less digits than its factorization.

21090328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2899 (or 2895 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 21090328 is about 4592.4207124348. The cubic root of 21090328 is about 276.2874202498.

The spelling of 21090328 in words is "twenty-one million, ninety thousand, three hundred twenty-eight".