20636965 has 4 divisors (see below), whose sum is σ = 24764364. Its totient is φ = 16509568.

The previous prime is 20636953. The next prime is 20637011. The reversal of 20636965 is 56963602.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56963602 = 2 ⋅28481801.

It can be written as a sum of positive squares in 2 ways, for example, as 5026564 + 15610401 = 2242^2 + 3951^2 .

It is a cyclic number.

It is not a de Polignac number, because 20636965 - 2¹⁵ = 20604197 is a prime.

It is a super-2 number, since 2×20636965² = 851768648822450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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, 2063692 + ... + 2063701.

It is an arithmetic number, because the mean of its divisors is an integer number (6191091).

Almost surely, 2^20636965 is an apocalyptic number.

It is an amenable number.

20636965 is a deficient number, since it is larger than the sum of its proper divisors (4127399).

20636965 is an equidigital number, since it uses as much as digits as its factorization.

20636965 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4127398.

The product of its (nonzero) digits is 58320, while the sum is 37.

The square root of 20636965 is about 4542.7926432977. The cubic root of 20636965 is about 274.2933482472.

The spelling of 20636965 in words is "twenty million, six hundred thirty-six thousand, nine hundred sixty-five".