2131664 has 30 divisors (see below), whose sum is σ = 4396854. Its totient is φ = 1000960.

The previous prime is 2131651. The next prime is 2131669. The reversal of 2131664 is 4661312.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 672400 + 1459264 = 820^2 + 1208^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2131669) 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 5 ways as a sum of consecutive naturals, for example, 4394 + ... + 4854.

2^2131664 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 2131664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2198427).

2131664 is an abundant number, since it is smaller than the sum of its proper divisors (2265190).

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

2131664 is a wasteful number, since it uses less digits than its factorization.

2131664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 503 (or 480 counting only the distinct ones).

The product of its digits is 864, while the sum is 23.

The square root of 2131664 is about 1460.0219176437. The cubic root of 2131664 is about 128.6983316102.

Adding to 2131664 its reverse (4661312), we get a palindrome (6792976).

It can be divided in two parts, 21316 and 64, that multiplied together give a square (1364224 = 1168²).

The spelling of 2131664 in words is "two million, one hundred thirty-one thousand, six hundred sixty-four".