36811561 has 2 divisors, whose sum is σ = 36811562. Its totient is φ = 36811560.

The previous prime is 36811553. The next prime is 36811591. The reversal of 36811561 is 16511863.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 23707161 + 13104400 = 4869^2 + 3620^2 .

It is an emirp because it is prime and its reverse (16511863) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 36811561 - 2³ = 36811553 is a prime.

It is not a weakly prime, because it can be changed into another prime (36811591) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 18405780 + 18405781.

It is an arithmetic number, because the mean of its divisors is an integer number (18405781).

Almost surely, 2^36811561 is an apocalyptic number.

It is an amenable number.

36811561 is a deficient number, since it is larger than the sum of its proper divisors (1).

36811561 is an equidigital number, since it uses as much as digits as its factorization.

36811561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4320, while the sum is 31.

The square root of 36811561 is about 6067.2531676204. The cubic root of 36811561 is about 332.6555278958.

The spelling of 36811561 in words is "thirty-six million, eight hundred eleven thousand, five hundred sixty-one".