21228599 has 8 divisors (see below), whose sum is σ = 24341280. Its totient is φ = 18135936.

The previous prime is 21228593. The next prime is 21228601. The reversal of 21228599 is 99582212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21228599 - 2¹² = 21224503 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21228593) 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, 2654 + ... + 7035.

It is an arithmetic number, because the mean of its divisors is an integer number (3042660).

Almost surely, 2^21228599 is an apocalyptic number.

21228599 is a deficient number, since it is larger than the sum of its proper divisors (3112681).

21228599 is an equidigital number, since it uses as much as digits as its factorization.

21228599 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10009.

The product of its digits is 25920, while the sum is 38.

The square root of 21228599 is about 4607.4503795483. The cubic root of 21228599 is about 276.8898978985.

The spelling of 21228599 in words is "twenty-one million, two hundred twenty-eight thousand, five hundred ninety-nine".