166402403 has 4 divisors (see below), whose sum is σ = 166710528. Its totient is φ = 166094280.

The previous prime is 166402367. The next prime is 166402421. The reversal of 166402403 is 304204661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 304204661 = 43 ⋅7074527.

It is a cyclic number.

It is not a de Polignac number, because 166402403 - 2⁸ = 166402147 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166402463) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 153251 + ... + 154332.

It is an arithmetic number, because the mean of its divisors is an integer number (41677632).

Almost surely, 2^166402403 is an apocalyptic number.

166402403 is a deficient number, since it is larger than the sum of its proper divisors (308125).

166402403 is an equidigital number, since it uses as much as digits as its factorization.

166402403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 308124.

The product of its (nonzero) digits is 3456, while the sum is 26.

The square root of 166402403 is about 12899.7055392749. The cubic root of 166402403 is about 550.0301944856.

The spelling of 166402403 in words is "one hundred sixty-six million, four hundred two thousand, four hundred three".