20871365 has 4 divisors (see below), whose sum is σ = 25045644. Its totient is φ = 16697088.

The previous prime is 20871353. The next prime is 20871379. The reversal of 20871365 is 56317802.

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 6385729 + 14485636 = 2527^2 + 3806^2 .

It is a cyclic number.

It is not a de Polignac number, because 20871365 - 2⁴ = 20871349 is a prime.

It is a super-2 number, since 2×20871365² = 871227753926450, which contains 22 as substring.

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, 2087132 + ... + 2087141.

It is an arithmetic number, because the mean of its divisors is an integer number (6261411).

Almost surely, 2^20871365 is an apocalyptic number.

It is an amenable number.

20871365 is a deficient number, since it is larger than the sum of its proper divisors (4174279).

20871365 is an equidigital number, since it uses as much as digits as its factorization.

20871365 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4174278.

The product of its (nonzero) digits is 10080, while the sum is 32.

The square root of 20871365 is about 4568.5189066042. The cubic root of 20871365 is about 275.3279393532.

The spelling of 20871365 in words is "twenty million, eight hundred seventy-one thousand, three hundred sixty-five".