21828290 has 16 divisors (see below), whose sum is σ = 42863040. Its totient is φ = 7937520.

The previous prime is 21828281. The next prime is 21828299. The reversal of 21828290 is 9282812.

It is an interprime number because it is at equal distance from previous prime (21828281) and next prime (21828299).

It is not an unprimeable number, because it can be changed into a prime (21828299) 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, 99110 + ... + 99329.

It is an arithmetic number, because the mean of its divisors is an integer number (2678940).

Almost surely, 2^21828290 is an apocalyptic number.

21828290 is a deficient number, since it is larger than the sum of its proper divisors (21034750).

21828290 is a wasteful number, since it uses less digits than its factorization.

21828290 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198457.

The product of its (nonzero) digits is 4608, while the sum is 32.

The square root of 21828290 is about 4672.0755558959. The cubic root of 21828290 is about 279.4730309583.

The spelling of 21828290 in words is "twenty-one million, eight hundred twenty-eight thousand, two hundred ninety".