2171656 has 16 divisors (see below), whose sum is σ = 4088700. Its totient is φ = 1081344.

The previous prime is 2171639. The next prime is 2171657. The reversal of 2171656 is 6561712.

It can be written as a sum of positive squares in 2 ways, for example, as 2149156 + 22500 = 1466^2 + 150^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2171657) 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, 2440 + ... + 3208.

2^2171656 is an apocalyptic number.

It is an amenable number.

2171656 is a deficient number, since it is larger than the sum of its proper divisors (1917044).

2171656 is a wasteful number, since it uses less digits than its factorization.

2171656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1128 (or 1124 counting only the distinct ones).

The product of its digits is 2520, while the sum is 28.

The square root of 2171656 is about 1473.6539620956. The cubic root of 2171656 is about 129.4981837623.

The spelling of 2171656 in words is "two million, one hundred seventy-one thousand, six hundred fifty-six".