1661331119985 has 12 divisors (see below), whose sum is σ = 2879640608052. Its totient is φ = 886043263968.

The previous prime is 1661331119977. The next prime is 1661331120023. The reversal of 1661331119985 is 5899111331661.

1661331119985 is a `hidden beast` number, since 1 + 6 + 61 + 3 + 311 + 199 + 85 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 409687044624 + 1251644075361 = 640068^2 + 1118769^2 .

It is not a de Polignac number, because 1661331119985 - 2³ = 1661331119977 is a prime.

It is a super-2 number, since 2×1661331119985² (a number of 25 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18459234622 + ... + 18459234711.

It is an arithmetic number, because the mean of its divisors is an integer number (239970050671).

Almost surely, 2^{1661331119985} is an apocalyptic number.

1661331119985 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1661331119985 is a deficient number, since it is larger than the sum of its proper divisors (1218309488067).

1661331119985 is a wasteful number, since it uses less digits than its factorization.

1661331119985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36918469344 (or 36918469341 counting only the distinct ones).

The product of its digits is 1049760, while the sum is 54.

The spelling of 1661331119985 in words is "one trillion, six hundred sixty-one billion, three hundred thirty-one million, one hundred nineteen thousand, nine hundred eighty-five".