166980881 has 2 divisors, whose sum is σ = 166980882. Its totient is φ = 166980880.

The previous prime is 166980871. The next prime is 166980887. The reversal of 166980881 is 188089661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 149206225 + 17774656 = 12215^2 + 4216^2 .

It is an emirp because it is prime and its reverse (188089661) is a distict prime. It is also a bemirp because it and its reverse can be mirrored producing other two distinct primes, 188086991 and 199680881.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-166980881 is a prime.

It is a super-2 number, since 2×166980881² = 55765229239072322, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (166980887) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83490440 + 83490441.

It is an arithmetic number, because the mean of its divisors is an integer number (83490441).

Almost surely, 2^166980881 is an apocalyptic number.

It is an amenable number.

166980881 is a deficient number, since it is larger than the sum of its proper divisors (1).

166980881 is an equidigital number, since it uses as much as digits as its factorization.

166980881 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 165888, while the sum is 47.

The square root of 166980881 is about 12922.1082258275. The cubic root of 166980881 is about 550.6668286652. Note that the first 3 decimals are identical.

The spelling of 166980881 in words is "one hundred sixty-six million, nine hundred eighty thousand, eight hundred eighty-one".