20155115009 has 2 divisors, whose sum is σ = 20155115010. Its totient is φ = 20155115008.

The previous prime is 20155114997. The next prime is 20155115023. The reversal of 20155115009 is 90051155102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14102275009 + 6052840000 = 118753^2 + 77800^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20155115009 is a prime.

It is a super-2 number, since 2×20155115009² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (20155115059) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10077557504 + 10077557505.

It is an arithmetic number, because the mean of its divisors is an integer number (10077557505).

Almost surely, 2^20155115009 is an apocalyptic number.

It is an amenable number.

20155115009 is a deficient number, since it is larger than the sum of its proper divisors (1).

20155115009 is an equidigital number, since it uses as much as digits as its factorization.

20155115009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2250, while the sum is 29.

The spelling of 20155115009 in words is "twenty billion, one hundred fifty-five million, one hundred fifteen thousand, nine".