21227513 has 2 divisors, whose sum is σ = 21227514. Its totient is φ = 21227512.

The previous prime is 21227501. The next prime is 21227527. The reversal of 21227513 is 31572212.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10936249 + 10291264 = 3307^2 + 3208^2 .

It is a cyclic number.

It is not a de Polignac number, because 21227513 - 2⁸ = 21227257 is a prime.

It is not a weakly prime, because it can be changed into another prime (21227533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10613756 + 10613757.

It is an arithmetic number, because the mean of its divisors is an integer number (10613757).

Almost surely, 2^21227513 is an apocalyptic number.

It is an amenable number.

21227513 is a deficient number, since it is larger than the sum of its proper divisors (1).

21227513 is an equidigital number, since it uses as much as digits as its factorization.

21227513 is an evil number, because the sum of its binary digits is even.

The product of its digits is 840, while the sum is 23.

The square root of 21227513 is about 4607.3325254425. The cubic root of 21227513 is about 276.8851761619.

Adding to 21227513 its reverse (31572212), we get a palindrome (52799725).

The spelling of 21227513 in words is "twenty-one million, two hundred twenty-seven thousand, five hundred thirteen".