2161728 has 84 divisors (see below), whose sum is σ = 6471920. Its totient is φ = 715392.

The previous prime is 2161699. The next prime is 2161729. The reversal of 2161728 is 8271612.

2161728 is a `hidden beast` number, since 21 + 617 + 28 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a nialpdrome in base 12.

It is not an unprimeable number, because it can be changed into a prime (2161729) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 15483 + ... + 15621.

2^2161728 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 2161728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3235960).

2161728 is an abundant number, since it is smaller than the sum of its proper divisors (4310192).

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

2161728 is an equidigital number, since it uses as much as digits as its factorization.

2161728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166 (or 144 counting only the distinct ones).

The product of its digits is 1344, while the sum is 27.

The square root of 2161728 is about 1470.2816056797. The cubic root of 2161728 is about 129.3005431688.

It can be divided in two parts, 216 and 1728, that multiplied together give a cube (373248 = 72³).

The spelling of 2161728 in words is "two million, one hundred sixty-one thousand, seven hundred twenty-eight".