20615120065 has 16 divisors (see below), whose sum is σ = 25092200016. Its totient is φ = 16256332800.

The previous prime is 20615120033. The next prime is 20615120069. The reversal of 20615120065 is 56002151602.

It can be written as a sum of positive squares in 8 ways, for example, as 353590416 + 20261529649 = 18804^2 + 142343^2 .

It is not a de Polignac number, because 20615120065 - 2⁵ = 20615120033 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20615120069) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 619245 + ... + 651685.

It is an arithmetic number, because the mean of its divisors is an integer number (1568262501).

Almost surely, 2^20615120065 is an apocalyptic number.

It is an amenable number.

20615120065 is a deficient number, since it is larger than the sum of its proper divisors (4477079951).

20615120065 is a wasteful number, since it uses less digits than its factorization.

20615120065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34260.

The product of its (nonzero) digits is 3600, while the sum is 28.

Adding to 20615120065 its reverse (56002151602), we get a palindrome (76617271667).

The spelling of 20615120065 in words is "twenty billion, six hundred fifteen million, one hundred twenty thousand, sixty-five".