161660811 has 16 divisors (see below), whose sum is σ = 232771616. Its totient is φ = 99207936.

The previous prime is 161660791. The next prime is 161660833. The reversal of 161660811 is 118066161.

It is a happy number.

It is not a de Polignac number, because 161660811 - 2⁶ = 161660747 is a prime.

It is a super-2 number, since 2×161660811² = 52268435626355442, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161660861) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8991 + ... + 20103.

It is an arithmetic number, because the mean of its divisors is an integer number (14548226).

Almost surely, 2^161660811 is an apocalyptic number.

161660811 is a deficient number, since it is larger than the sum of its proper divisors (71110805).

161660811 is a wasteful number, since it uses less digits than its factorization.

161660811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11502.

The product of its (nonzero) digits is 1728, while the sum is 30.

The square root of 161660811 is about 12714.5904770858. The cubic root of 161660811 is about 544.7554507022.

The spelling of 161660811 in words is "one hundred sixty-one million, six hundred sixty thousand, eight hundred eleven".