20865081 has 4 divisors (see below), whose sum is σ = 27820112. Its totient is φ = 13910052.

The previous prime is 20865067. The next prime is 20865083. The reversal of 20865081 is 18056802.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 20865081 - 2⁶ = 20865017 is a prime.

It is a super-2 number, since 2×20865081² = 870703210273122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20865083) 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, 3477511 + ... + 3477516.

It is an arithmetic number, because the mean of its divisors is an integer number (6955028).

Almost surely, 2^20865081 is an apocalyptic number.

It is an amenable number.

20865081 is a deficient number, since it is larger than the sum of its proper divisors (6955031).

20865081 is an equidigital number, since it uses as much as digits as its factorization.

20865081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6955030.

The product of its (nonzero) digits is 3840, while the sum is 30.

The square root of 20865081 is about 4567.8311045834. The cubic root of 20865081 is about 275.3003044502.

The spelling of 20865081 in words is "twenty million, eight hundred sixty-five thousand, eighty-one".