21328090 has 16 divisors (see below), whose sum is σ = 43875072. Its totient is φ = 7312464.

The previous prime is 21328067. The next prime is 21328103. The reversal of 21328090 is 9082312.

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, 152274 + ... + 152413.

It is an arithmetic number, because the mean of its divisors is an integer number (2742192).

Almost surely, 2^21328090 is an apocalyptic number.

21328090 is an abundant number, since it is smaller than the sum of its proper divisors (22546982).

21328090 is a wasteful number, since it uses less digits than its factorization.

21328090 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 304701.

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

The square root of 21328090 is about 4618.2345111525. The cubic root of 21328090 is about 277.3217858517.

The spelling of 21328090 in words is "twenty-one million, three hundred twenty-eight thousand, ninety".