1665161811 has 6 divisors (see below), whose sum is σ = 2405233740. Its totient is φ = 1110107868.

The previous prime is 1665161803. The next prime is 1665161831. The reversal of 1665161811 is 1181615661.

1665161811 is a `hidden beast` number, since 1 + 66 + 516 + 1 + 81 + 1 = 666.

It is not a de Polignac number, because 1665161811 - 2³ = 1665161803 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1665161831) 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 5 ways as a sum of consecutive naturals, for example, 92508981 + ... + 92508998.

It is an arithmetic number, because the mean of its divisors is an integer number (400872290).

Almost surely, 2^1665161811 is an apocalyptic number.

1665161811 is a deficient number, since it is larger than the sum of its proper divisors (740071929).

1665161811 is a wasteful number, since it uses less digits than its factorization.

1665161811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 185017985 (or 185017982 counting only the distinct ones).

The product of its digits is 8640, while the sum is 36.

The square root of 1665161811 is about 40806.3942415891. The cubic root of 1665161811 is about 1185.2741533077.

The spelling of 1665161811 in words is "one billion, six hundred sixty-five million, one hundred sixty-one thousand, eight hundred eleven".