1668122181 has 40 divisors (see below), whose sum is σ = 2738181600. Its totient is φ = 1003635360.

The previous prime is 1668122179. The next prime is 1668122191. The reversal of 1668122181 is 1812218661.

It is not a de Polignac number, because 1668122181 - 2¹ = 1668122179 is a prime.

It is a super-2 number, since 2×1668122181² = 5565263221488393522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1668122111) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 117115 + ... + 130583.

It is an arithmetic number, because the mean of its divisors is an integer number (68454540).

Almost surely, 2^1668122181 is an apocalyptic number.

1668122181 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1668122181 is a deficient number, since it is larger than the sum of its proper divisors (1070059419).

1668122181 is a wasteful number, since it uses less digits than its factorization.

1668122181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13631 (or 13622 counting only the distinct ones).

The product of its digits is 9216, while the sum is 36.

The square root of 1668122181 is about 40842.6514932613. The cubic root of 1668122181 is about 1185.9761416864.

The spelling of 1668122181 in words is "one billion, six hundred sixty-eight million, one hundred twenty-two thousand, one hundred eighty-one".