21362513 has 2 divisors, whose sum is σ = 21362514. Its totient is φ = 21362512.

The previous prime is 21362477. The next prime is 21362521. The reversal of 21362513 is 31526312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19963024 + 1399489 = 4468^2 + 1183^2 .

It is a cyclic number.

It is not a de Polignac number, because 21362513 - 2¹⁰ = 21361489 is a prime.

It is equal to p_1351418 and since 21362513 and 1351418 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (21362533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10681256 + 10681257.

It is an arithmetic number, because the mean of its divisors is an integer number (10681257).

Almost surely, 2^21362513 is an apocalyptic number.

It is an amenable number.

21362513 is a deficient number, since it is larger than the sum of its proper divisors (1).

21362513 is an equidigital number, since it uses as much as digits as its factorization.

21362513 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1080, while the sum is 23.

The square root of 21362513 is about 4621.9598656847. The cubic root of 21362513 is about 277.4709024491.

Adding to 21362513 its reverse (31526312), we get a palindrome (52888825).

It can be divided in two parts, 213 and 62513, that added together give a palindrome (62726).

The spelling of 21362513 in words is "twenty-one million, three hundred sixty-two thousand, five hundred thirteen".