2156688 has 60 divisors (see below), whose sum is σ = 6398028. Its totient is φ = 675840.

The previous prime is 2156683. The next prime is 2156699. The reversal of 2156688 is 8866512.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 1016064 + 1140624 = 1008^2 + 1068^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (2156681) 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 11 ways as a sum of consecutive naturals, for example, 2008 + ... + 2888.

2^2156688 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2156688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3199014).

2156688 is an abundant number, since it is smaller than the sum of its proper divisors (4241340).

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

2156688 is a wasteful number, since it uses less digits than its factorization.

2156688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 912 (or 903 counting only the distinct ones).

The product of its digits is 23040, while the sum is 36.

The square root of 2156688 is about 1468.5666481301. The cubic root of 2156688 is about 129.1999782739.

It can be divided in two parts, 215 and 6688, that added together give a triangular number (6903 = T₁₁₇).

The spelling of 2156688 in words is "two million, one hundred fifty-six thousand, six hundred eighty-eight".