161660511 has 24 divisors (see below), whose sum is σ = 242751600. Its totient is φ = 103579776.

The previous prime is 161660507. The next prime is 161660519. The reversal of 161660511 is 115066161.

It is not a de Polignac number, because 161660511 - 2² = 161660507 is a prime.

It is a super-2 number, since 2×161660511² = 52268241633562242, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161660519) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 24715 + ... + 30563.

It is an arithmetic number, because the mean of its divisors is an integer number (10114650).

Almost surely, 2^161660511 is an apocalyptic number.

161660511 is a deficient number, since it is larger than the sum of its proper divisors (81091089).

161660511 is a wasteful number, since it uses less digits than its factorization.

161660511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5975 (or 5972 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 27.

The square root of 161660511 is about 12714.5786796103. The cubic root of 161660511 is about 544.7551137277.

The spelling of 161660511 in words is "one hundred sixty-one million, six hundred sixty thousand, five hundred eleven".