21965369 has 4 divisors (see below), whose sum is σ = 22230096. Its totient is φ = 21700644.

The previous prime is 21965357. The next prime is 21965371. The reversal of 21965369 is 96356912.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21965369 - 2⁸ = 21965113 is a prime.

It is a super-2 number, since 2×21965369² = 964954870612322, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21965569) 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 in 3 ways as a sum of consecutive naturals, for example, 132239 + ... + 132404.

It is an arithmetic number, because the mean of its divisors is an integer number (5557524).

Almost surely, 2^21965369 is an apocalyptic number.

It is an amenable number.

21965369 is a deficient number, since it is larger than the sum of its proper divisors (264727).

21965369 is an equidigital number, since it uses as much as digits as its factorization.

21965369 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 264726.

The product of its digits is 87480, while the sum is 41.

The square root of 21965369 is about 4686.7226288740. The cubic root of 21965369 is about 280.0568294514.

The spelling of 21965369 in words is "twenty-one million, nine hundred sixty-five thousand, three hundred sixty-nine".