166921940 has 12 divisors (see below), whose sum is σ = 350536116. Its totient is φ = 66768768.

The previous prime is 166921927. The next prime is 166922009. The reversal of 166921940 is 49129661.

166921940 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 55323844 + 111598096 = 7438^2 + 10564^2 .

It is a junction number, because it is equal to n+sod(n) for n = 166921894 and 166921903.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4173029 + ... + 4173068.

It is an arithmetic number, because the mean of its divisors is an integer number (29211343).

Almost surely, 2^166921940 is an apocalyptic number.

166921940 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

166921940 is an abundant number, since it is smaller than the sum of its proper divisors (183614176).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

166921940 is a wasteful number, since it uses less digits than its factorization.

166921940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8346106 (or 8346104 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 38.

The square root of 166921940 is about 12919.8273982279. The cubic root of 166921940 is about 550.6020294839.

The spelling of 166921940 in words is "one hundred sixty-six million, nine hundred twenty-one thousand, nine hundred forty".