2171956 has 12 divisors (see below), whose sum is σ = 3844260. Its totient is φ = 1073600.

The previous prime is 2171951. The next prime is 2171963. The reversal of 2171956 is 6591712.

It can be written as a sum of positive squares in 2 ways, for example, as 872356 + 1299600 = 934^2 + 1140^2 .

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2171951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2695 + ... + 3406.

It is an arithmetic number, because the mean of its divisors is an integer number (320355).

2^2171956 is an apocalyptic number.

It is an amenable number.

2171956 is a deficient number, since it is larger than the sum of its proper divisors (1672304).

2171956 is a wasteful number, since it uses less digits than its factorization.

2171956 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6194 (or 6192 counting only the distinct ones).

The product of its digits is 3780, while the sum is 31.

The square root of 2171956 is about 1473.7557463840. The cubic root of 2171956 is about 129.5041465953.

The spelling of 2171956 in words is "two million, one hundred seventy-one thousand, nine hundred fifty-six".