111665153457661 has 2 divisors, whose sum is σ = 111665153457662. Its totient is φ = 111665153457660.

The previous prime is 111665153457659. The next prime is 111665153457707. The reversal of 111665153457661 is 166754351566111.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 96819814166436 + 14845339291225 = 9839706^2 + 3852965^2 .

It is a cyclic number.

It is not a de Polignac number, because 111665153457661 - 2¹ = 111665153457659 is a prime.

Together with 111665153457659, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 111665153457596 and 111665153457605.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (111665153457161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55832576728830 + 55832576728831.

It is an arithmetic number, because the mean of its divisors is an integer number (55832576728831).

Almost surely, 2^{111665153457661} is an apocalyptic number.

It is an amenable number.

111665153457661 is a deficient number, since it is larger than the sum of its proper divisors (1).

111665153457661 is an equidigital number, since it uses as much as digits as its factorization.

111665153457661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13608000, while the sum is 58.

The spelling of 111665153457661 in words is "one hundred eleven trillion, six hundred sixty-five billion, one hundred fifty-three million, four hundred fifty-seven thousand, six hundred sixty-one".