20565122015 has 4 divisors (see below), whose sum is σ = 24678146424. Its totient is φ = 16452097608.

The previous prime is 20565122009. The next prime is 20565122021. The reversal of 20565122015 is 51022156502.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (20565122009) and next prime (20565122021).

It is a cyclic number.

It is not a de Polignac number, because 20565122015 - 2³⁴ = 3385252831 is a prime.

It is a Duffinian number.

It is a congruent 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, 2056512197 + ... + 2056512206.

It is an arithmetic number, because the mean of its divisors is an integer number (6169536606).

Almost surely, 2^20565122015 is an apocalyptic number.

20565122015 is a deficient number, since it is larger than the sum of its proper divisors (4113024409).

20565122015 is an equidigital number, since it uses as much as digits as its factorization.

20565122015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4113024408.

The product of its (nonzero) digits is 6000, while the sum is 29.

Adding to 20565122015 its reverse (51022156502), we get a palindrome (71587278517).

The spelling of 20565122015 in words is "twenty billion, five hundred sixty-five million, one hundred twenty-two thousand, fifteen".