21436339 has 2 divisors, whose sum is σ = 21436340. Its totient is φ = 21436338.

The previous prime is 21436333. The next prime is 21436343. The reversal of 21436339 is 93363412.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21436339 is a prime.

It is equal to p_1355791 and since 21436339 and 1355791 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21436339.

It is not a weakly prime, because it can be changed into another prime (21436333) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10718169 + 10718170.

It is an arithmetic number, because the mean of its divisors is an integer number (10718170).

Almost surely, 2^21436339 is an apocalyptic number.

21436339 is a deficient number, since it is larger than the sum of its proper divisors (1).

21436339 is an equidigital number, since it uses as much as digits as its factorization.

21436339 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11664, while the sum is 31.

The square root of 21436339 is about 4629.9394164503. The cubic root of 21436339 is about 277.7901691124.

It can be divided in two parts, 2 and 1436339, that added together give a palindrome (1436341).

The spelling of 21436339 in words is "twenty-one million, four hundred thirty-six thousand, three hundred thirty-nine".