2161312 has 48 divisors (see below), whose sum is σ = 4694760. Its totient is φ = 974848.

The previous prime is 2161303. The next prime is 2161319. The reversal of 2161312 is 2131612.

It can be written as a sum of positive squares in 4 ways, for example, as 2085136 + 76176 = 1444^2 + 276^2 .

It is a super-2 number, since 2×2161312² = 9342539122688, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is not an unprimeable number, because it can be changed into a prime (2161319) 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, 15708 + ... + 15844.

2^2161312 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 2161312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2347380).

2161312 is an abundant number, since it is smaller than the sum of its proper divisors (2533448).

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

2161312 is a wasteful number, since it uses less digits than its factorization.

2161312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 193 (or 185 counting only the distinct ones).

The product of its digits is 72, while the sum is 16.

The square root of 2161312 is about 1470.1401293754. The cubic root of 2161312 is about 129.2922484964.

Adding to 2161312 its reverse (2131612), we get a palindrome (4292924).

It can be divided in two parts, 2 and 161312, that multiplied together give a square (322624 = 568²).

The spelling of 2161312 in words is "two million, one hundred sixty-one thousand, three hundred twelve".