20515520065 has 4 divisors (see below), whose sum is σ = 24618624084. Its totient is φ = 16412416048.

The previous prime is 20515520057. The next prime is 20515520071. The reversal of 20515520065 is 56002551502.

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 3728689969 + 16786830096 = 61063^2 + 129564^2 .

It is a cyclic number.

It is not a de Polignac number, because 20515520065 - 2³ = 20515520057 is a prime.

It is a Duffinian 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, 2051552002 + ... + 2051552011.

It is an arithmetic number, because the mean of its divisors is an integer number (6154656021).

Almost surely, 2^20515520065 is an apocalyptic number.

It is an amenable number.

20515520065 is a deficient number, since it is larger than the sum of its proper divisors (4103104019).

20515520065 is an equidigital number, since it uses as much as digits as its factorization.

20515520065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4103104018.

The product of its (nonzero) digits is 15000, while the sum is 31.

The spelling of 20515520065 in words is "twenty billion, five hundred fifteen million, five hundred twenty thousand, sixty-five".