21435769 has 2 divisors, whose sum is σ = 21435770. Its totient is φ = 21435768.

The previous prime is 21435751. The next prime is 21435833. The reversal of 21435769 is 96753412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17749369 + 3686400 = 4213^2 + 1920^2 .

It is a cyclic number.

It is not a de Polignac number, because 21435769 - 2⁵ = 21435737 is a prime.

It is a super-2 number, since 2×21435769² = 918984385242722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21435719) 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, 10717884 + 10717885.

It is an arithmetic number, because the mean of its divisors is an integer number (10717885).

Almost surely, 2^21435769 is an apocalyptic number.

It is an amenable number.

21435769 is a deficient number, since it is larger than the sum of its proper divisors (1).

21435769 is an equidigital number, since it uses as much as digits as its factorization.

21435769 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 45360, while the sum is 37.

The square root of 21435769 is about 4629.8778601600. The cubic root of 21435769 is about 277.7877069103.

The spelling of 21435769 in words is "twenty-one million, four hundred thirty-five thousand, seven hundred sixty-nine".