161660111 has 2 divisors, whose sum is σ = 161660112. Its totient is φ = 161660110.

The previous prime is 161660101. The next prime is 161660131. The reversal of 161660111 is 111066161.

It is a weak prime.

It is an emirp because it is prime and its reverse (111066161) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 161660111 - 2⁶ = 161660047 is a prime.

It is a super-2 number, since 2×161660111² = 52267982977064642, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161660101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80830055 + 80830056.

It is an arithmetic number, because the mean of its divisors is an integer number (80830056).

Almost surely, 2^161660111 is an apocalyptic number.

161660111 is a deficient number, since it is larger than the sum of its proper divisors (1).

161660111 is an equidigital number, since it uses as much as digits as its factorization.

161660111 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216, while the sum is 23.

The square root of 161660111 is about 12714.5629496259. The cubic root of 161660111 is about 544.7546644276.

The spelling of 161660111 in words is "one hundred sixty-one million, six hundred sixty thousand, one hundred eleven".