36161981 has 2 divisors, whose sum is σ = 36161982. Its totient is φ = 36161980.

The previous prime is 36161971. The next prime is 36161989. The reversal of 36161981 is 18916163.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 31922500 + 4239481 = 5650^2 + 2059^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-36161981 is a prime.

It is a super-2 number, since 2×36161981² = 2615377739688722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (36161989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 18080990 + 18080991.

It is an arithmetic number, because the mean of its divisors is an integer number (18080991).

Almost surely, 2^36161981 is an apocalyptic number.

It is an amenable number.

36161981 is a deficient number, since it is larger than the sum of its proper divisors (1).

36161981 is an equidigital number, since it uses as much as digits as its factorization.

36161981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7776, while the sum is 35.

The square root of 36161981 is about 6013.4832667930. The cubic root of 36161981 is about 330.6872149791.

The spelling of 36161981 in words is "thirty-six million, one hundred sixty-one thousand, nine hundred eighty-one".