161511666 has 16 divisors (see below), whose sum is σ = 340024800. Its totient is φ = 51003648.

The previous prime is 161511661. The next prime is 161511667. The reversal of 161511666 is 666115161.

It is not an unprimeable number, because it can be changed into a prime (161511661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 708271 + ... + 708498.

It is an arithmetic number, because the mean of its divisors is an integer number (21251550).

Almost surely, 2^161511666 is an apocalyptic number.

161511666 is an abundant number, since it is smaller than the sum of its proper divisors (178513134).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161511666 is a wasteful number, since it uses less digits than its factorization.

161511666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1416793.

The product of its digits is 6480, while the sum is 33.

The square root of 161511666 is about 12708.7240114812. The cubic root of 161511666 is about 544.5878723638.

The spelling of 161511666 in words is "one hundred sixty-one million, five hundred eleven thousand, six hundred sixty-six".