20316220865 has 4 divisors (see below), whose sum is σ = 24379465044. Its totient is φ = 16252976688.

The previous prime is 20316220843. The next prime is 20316220867. The reversal of 20316220865 is 56802261302.

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 14080907569 + 6235313296 = 118663^2 + 78964^2 .

It is a cyclic number.

It is not a de Polignac number, because 20316220865 - 2⁸ = 20316220609 is a prime.

It is a super-2 number, since 2×20316220865² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20316220867) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2031622082 + ... + 2031622091.

It is an arithmetic number, because the mean of its divisors is an integer number (6094866261).

Almost surely, 2^20316220865 is an apocalyptic number.

It is an amenable number.

20316220865 is a deficient number, since it is larger than the sum of its proper divisors (4063244179).

20316220865 is an equidigital number, since it uses as much as digits as its factorization.

20316220865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4063244178.

The product of its (nonzero) digits is 34560, while the sum is 35.

The spelling of 20316220865 in words is "twenty billion, three hundred sixteen million, two hundred twenty thousand, eight hundred sixty-five".