20308865 has 8 divisors (see below), whose sum is σ = 24478440. Its totient is φ = 16175232.

The previous prime is 20308861. The next prime is 20308867. The reversal of 20308865 is 56880302.

It can be written as a sum of positive squares in 4 ways, for example, as 10316944 + 9991921 = 3212^2 + 3161^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20308865 - 2² = 20308861 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20308861) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7724 + ... + 10013.

It is an arithmetic number, because the mean of its divisors is an integer number (3059805).

Almost surely, 2^20308865 is an apocalyptic number.

It is an amenable number.

20308865 is a deficient number, since it is larger than the sum of its proper divisors (4169575).

20308865 is a wasteful number, since it uses less digits than its factorization.

20308865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17971.

The product of its (nonzero) digits is 11520, while the sum is 32.

The square root of 20308865 is about 4506.5358092442. The cubic root of 20308865 is about 272.8319440481.

The spelling of 20308865 in words is "twenty million, three hundred eight thousand, eight hundred sixty-five".