166451819 has 2 divisors, whose sum is σ = 166451820. Its totient is φ = 166451818.

The previous prime is 166451809. The next prime is 166451821. The reversal of 166451819 is 918154661.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-166451819 is a prime.

It is a super-2 number, since 2×166451819² = 55412416096817522, which contains 22 as substring.

Together with 166451821, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (166451809) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83225909 + 83225910.

It is an arithmetic number, because the mean of its divisors is an integer number (83225910).

Almost surely, 2^166451819 is an apocalyptic number.

166451819 is a deficient number, since it is larger than the sum of its proper divisors (1).

166451819 is an equidigital number, since it uses as much as digits as its factorization.

166451819 is an evil number, because the sum of its binary digits is even.

The product of its digits is 51840, while the sum is 41.

The square root of 166451819 is about 12901.6207896527. The cubic root of 166451819 is about 550.0846360110.

The spelling of 166451819 in words is "one hundred sixty-six million, four hundred fifty-one thousand, eight hundred nineteen".