21326245 has 16 divisors (see below), whose sum is σ = 27833328. Its totient is φ = 15621120.

The previous prime is 21326231. The next prime is 21326309. The reversal of 21326245 is 54262312.

It can be written as a sum of positive squares in 8 ways, for example, as 1532644 + 19793601 = 1238^2 + 4449^2 .

It is not a de Polignac number, because 21326245 - 2⁵ = 21326213 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 246 + ... + 6535.

It is an arithmetic number, because the mean of its divisors is an integer number (1739583).

Almost surely, 2^21326245 is an apocalyptic number.

It is an amenable number.

21326245 is a deficient number, since it is larger than the sum of its proper divisors (6507083).

21326245 is a wasteful number, since it uses less digits than its factorization.

21326245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6840.

The product of its digits is 2880, while the sum is 25.

The square root of 21326245 is about 4618.0347551745. The cubic root of 21326245 is about 277.3137889886.

Adding to 21326245 its reverse (54262312), we get a palindrome (75588557).

The spelling of 21326245 in words is "twenty-one million, three hundred twenty-six thousand, two hundred forty-five".