166921903 has 16 divisors (see below), whose sum is σ = 172972800. Its totient is φ = 161029440.

The previous prime is 166921891. The next prime is 166921907. The reversal of 166921903 is 309129661.

It is a cyclic number.

It is not a de Polignac number, because 166921903 - 2⁵ = 166921871 is a prime.

It is a super-2 number, since 2×166921903² = 55725843402282818, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166921907) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1200808 + ... + 1200946.

It is an arithmetic number, because the mean of its divisors is an integer number (10810800).

Almost surely, 2^166921903 is an apocalyptic number.

166921903 is a deficient number, since it is larger than the sum of its proper divisors (6050897).

166921903 is a wasteful number, since it uses less digits than its factorization.

166921903 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 462.

The product of its (nonzero) digits is 17496, while the sum is 37.

The square root of 166921903 is about 12919.8259663201. The cubic root of 166921903 is about 550.6019888016.

The spelling of 166921903 in words is "one hundred sixty-six million, nine hundred twenty-one thousand, nine hundred three".