36665555211581 has 2 divisors, whose sum is σ = 36665555211582. Its totient is φ = 36665555211580.

The previous prime is 36665555211569. The next prime is 36665555211599. The reversal of 36665555211581 is 18511255556663.

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., 34810059000025 + 1855496211556 = 5900005^2 + 1362166^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-36665555211581 is a prime.

It is a super-2 number, since 2×36665555211581² (a number of 28 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 36665555211581.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (36665555211281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 18332777605790 + 18332777605791.

It is an arithmetic number, because the mean of its divisors is an integer number (18332777605791).

Almost surely, 2^{36665555211581} is an apocalyptic number.

It is an amenable number.

36665555211581 is a deficient number, since it is larger than the sum of its proper divisors (1).

36665555211581 is an equidigital number, since it uses as much as digits as its factorization.

36665555211581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 32400000, while the sum is 59.

The spelling of 36665555211581 in words is "thirty-six trillion, six hundred sixty-five billion, five hundred fifty-five million, two hundred eleven thousand, five hundred eighty-one".