20897365 has 4 divisors (see below), whose sum is σ = 25076844. Its totient is φ = 16717888.

The previous prime is 20897353. The next prime is 20897377. The reversal of 20897365 is 56379802.

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

It is an interprime number because it is at equal distance from previous prime (20897353) and next prime (20897377).

It can be written as a sum of positive squares in 2 ways, for example, as 2979076 + 17918289 = 1726^2 + 4233^2 .

It is a cyclic number.

It is not a de Polignac number, because 20897365 - 2⁷ = 20897237 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, 2089732 + ... + 2089741.

It is an arithmetic number, because the mean of its divisors is an integer number (6269211).

Almost surely, 2^20897365 is an apocalyptic number.

It is an amenable number.

20897365 is a deficient number, since it is larger than the sum of its proper divisors (4179479).

20897365 is an equidigital number, since it uses as much as digits as its factorization.

20897365 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4179478.

The product of its (nonzero) digits is 90720, while the sum is 40.

The square root of 20897365 is about 4571.3635821273. The cubic root of 20897365 is about 275.4422196276.

The spelling of 20897365 in words is "twenty million, eight hundred ninety-seven thousand, three hundred sixty-five".