21328574 has 16 divisors (see below), whose sum is σ = 34215696. Its totient is φ = 9936000.

The previous prime is 21328561. The next prime is 21328597. The reversal of 21328574 is 47582312.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21328574.

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, 329 + ... + 6539.

It is an arithmetic number, because the mean of its divisors is an integer number (2138481).

Almost surely, 2^21328574 is an apocalyptic number.

21328574 is a deficient number, since it is larger than the sum of its proper divisors (12887122).

21328574 is a wasteful number, since it uses less digits than its factorization.

21328574 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6331.

The product of its digits is 13440, while the sum is 32.

The square root of 21328574 is about 4618.2869118321. The cubic root of 21328574 is about 277.3238835974.

The spelling of 21328574 in words is "twenty-one million, three hundred twenty-eight thousand, five hundred seventy-four".