1661166155 has 32 divisors (see below), whose sum is σ = 2256961536. Its totient is φ = 1162800000.

The previous prime is 1661166151. The next prime is 1661166281. The reversal of 1661166155 is 5516611661.

It is not a de Polignac number, because 1661166155 - 2² = 1661166151 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1661166151) 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 31 ways as a sum of consecutive naturals, for example, 323105 + ... + 328205.

It is an arithmetic number, because the mean of its divisors is an integer number (70530048).

Almost surely, 2^1661166155 is an apocalyptic number.

1661166155 is a deficient number, since it is larger than the sum of its proper divisors (595795381).

1661166155 is a wasteful number, since it uses less digits than its factorization.

1661166155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5339.

The product of its digits is 32400, while the sum is 38.

The square root of 1661166155 is about 40757.4061367992. The cubic root of 1661166155 is about 1184.3253484382.

It can be divided in two parts, 166116 and 6155, that added together give a palindrome (172271).

The spelling of 1661166155 in words is "one billion, six hundred sixty-one million, one hundred sixty-six thousand, one hundred fifty-five".