21413569 has 2 divisors, whose sum is σ = 21413570. Its totient is φ = 21413568.

The previous prime is 21413549. The next prime is 21413599. The reversal of 21413569 is 96531412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21344400 + 69169 = 4620^2 + 263^2 .

It is a cyclic number.

It is not a de Polignac number, because 21413569 - 2¹⁷ = 21282497 is a prime.

It is a super-2 number, since 2×21413569² = 917081874635522, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21413569.

It is not a weakly prime, because it can be changed into another prime (21413549) 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 as a sum of consecutive naturals, namely, 10706784 + 10706785.

It is an arithmetic number, because the mean of its divisors is an integer number (10706785).

Almost surely, 2^21413569 is an apocalyptic number.

It is an amenable number.

21413569 is a deficient number, since it is larger than the sum of its proper divisors (1).

21413569 is an equidigital number, since it uses as much as digits as its factorization.

21413569 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6480, while the sum is 31.

The square root of 21413569 is about 4627.4797676489. The cubic root of 21413569 is about 277.6917766416.

The spelling of 21413569 in words is "twenty-one million, four hundred thirteen thousand, five hundred sixty-nine".