2161906 has 16 divisors (see below), whose sum is σ = 3358080. Its totient is φ = 1043280.

The previous prime is 2161903. The next prime is 2161919. The reversal of 2161906 is 6091612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2161903) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10141 + ... + 10351.

It is an arithmetic number, because the mean of its divisors is an integer number (209880).

2^2161906 is an apocalyptic number.

2161906 is a deficient number, since it is larger than the sum of its proper divisors (1196174).

2161906 is a wasteful number, since it uses less digits than its factorization.

2161906 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 369.

The product of its (nonzero) digits is 648, while the sum is 25.

The square root of 2161906 is about 1470.3421370552. The cubic root of 2161906 is about 129.3040920064.

The spelling of 2161906 in words is "two million, one hundred sixty-one thousand, nine hundred six".