166378819 has 12 divisors (see below), whose sum is σ = 172032336. Its totient is φ = 160852848.

The previous prime is 166378783. The next prime is 166378831. The reversal of 166378819 is 918873661.

It is not a de Polignac number, because 166378819 - 2²⁵ = 132824387 is a prime.

It is a super-2 number, since 2×166378819² = 55363822823669522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166378859) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 330522 + ... + 331024.

It is an arithmetic number, because the mean of its divisors is an integer number (14336028).

Almost surely, 2^166378819 is an apocalyptic number.

166378819 is a deficient number, since it is larger than the sum of its proper divisors (5653517).

166378819 is an frugal number, since it uses more digits than its factorization.

166378819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 714 (or 635 counting only the distinct ones).

The product of its digits is 435456, while the sum is 49.

The square root of 166378819 is about 12898.7913774896. The cubic root of 166378819 is about 550.0042082323.

The spelling of 166378819 in words is "one hundred sixty-six million, three hundred seventy-eight thousand, eight hundred nineteen".