36155531561 has 2 divisors, whose sum is σ = 36155531562. Its totient is φ = 36155531560.

The previous prime is 36155531557. The next prime is 36155531593. The reversal of 36155531561 is 16513555163.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 36031632400 + 123899161 = 189820^2 + 11131^2 .

It is a cyclic number.

It is not a de Polignac number, because 36155531561 - 2² = 36155531557 is a prime.

It is not a weakly prime, because it can be changed into another prime (36155531161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 18077765780 + 18077765781.

It is an arithmetic number, because the mean of its divisors is an integer number (18077765781).

Almost surely, 2^36155531561 is an apocalyptic number.

It is an amenable number.

36155531561 is a deficient number, since it is larger than the sum of its proper divisors (1).

36155531561 is an equidigital number, since it uses as much as digits as its factorization.

36155531561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 202500, while the sum is 41.

The spelling of 36155531561 in words is "thirty-six billion, one hundred fifty-five million, five hundred thirty-one thousand, five hundred sixty-one".