21395369 has 4 divisors (see below), whose sum is σ = 21442644. Its totient is φ = 21348096.

The previous prime is 21395329. The next prime is 21395383. The reversal of 21395369 is 96359312.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 17347225 + 4048144 = 4165^2 + 2012^2 .

It is a cyclic number.

It is not a de Polignac number, because 21395369 - 2²⁰ = 20346793 is a prime.

It is a super-2 number, since 2×21395369² = 915523629292322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21395329) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22952 + ... + 23865.

It is an arithmetic number, because the mean of its divisors is an integer number (5360661).

Almost surely, 2^21395369 is an apocalyptic number.

It is an amenable number.

21395369 is a deficient number, since it is larger than the sum of its proper divisors (47275).

21395369 is an equidigital number, since it uses as much as digits as its factorization.

21395369 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47274.

The product of its digits is 43740, while the sum is 38.

The square root of 21395369 is about 4625.5128364323. The cubic root of 21395369 is about 277.6130816351.

The spelling of 21395369 in words is "twenty-one million, three hundred ninety-five thousand, three hundred sixty-nine".