21224597 has 4 divisors (see below), whose sum is σ = 21287916. Its totient is φ = 21161280.

The previous prime is 21224591. The next prime is 21224617. The reversal of 21224597 is 79542212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 10407076 + 10817521 = 3226^2 + 3289^2 .

It is a cyclic number.

It is not a de Polignac number, because 21224597 - 2¹² = 21220501 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 (21224591) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31154 + ... + 31827.

It is an arithmetic number, because the mean of its divisors is an integer number (5321979).

Almost surely, 2^21224597 is an apocalyptic number.

It is an amenable number.

21224597 is a deficient number, since it is larger than the sum of its proper divisors (63319).

21224597 is an equidigital number, since it uses as much as digits as its factorization.

21224597 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63318.

The product of its digits is 10080, while the sum is 32.

The square root of 21224597 is about 4607.0160624856. The cubic root of 21224597 is about 276.8724971111.

The spelling of 21224597 in words is "twenty-one million, two hundred twenty-four thousand, five hundred ninety-seven".