21935965 has 4 divisors (see below), whose sum is σ = 26323164. Its totient is φ = 17548768.

The previous prime is 21935939. The next prime is 21935983. The reversal of 21935965 is 56953912.

It is a happy number.

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 8231161 + 13704804 = 2869^2 + 3702^2 .

It is a cyclic number.

It is not a de Polignac number, because 21935965 - 2¹⁵ = 21903197 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2193592 + ... + 2193601.

It is an arithmetic number, because the mean of its divisors is an integer number (6580791).

Almost surely, 2^21935965 is an apocalyptic number.

It is an amenable number.

21935965 is a deficient number, since it is larger than the sum of its proper divisors (4387199).

21935965 is an equidigital number, since it uses as much as digits as its factorization.

21935965 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4387198.

The product of its digits is 72900, while the sum is 40.

The square root of 21935965 is about 4683.5846314548. The cubic root of 21935965 is about 279.9318073730.

The spelling of 21935965 in words is "twenty-one million, nine hundred thirty-five thousand, nine hundred sixty-five".