2123640 has 96 divisors (see below), whose sum is σ = 7328880. Its totient is φ = 531456.

The previous prime is 2123617. The next prime is 2123663. The reversal of 2123640 is 463212.

It is a happy number.

2123640 is a `hidden beast` number, since 2 + 1 + 23 + 640 = 666.

It is an interprime number because it is at equal distance from previous prime (2123617) and next prime (2123663).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5947 + ... + 6293.

2^2123640 is an apocalyptic number.

2123640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2123640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3664440).

2123640 is an abundant number, since it is smaller than the sum of its proper divisors (5205240).

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

2123640 is a wasteful number, since it uses less digits than its factorization.

2123640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 381 (or 374 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 2123640 is about 1457.2714228997. The cubic root of 2123640 is about 128.5366466761.

Adding to 2123640 its reverse (463212), we get a palindrome (2586852).

The spelling of 2123640 in words is "two million, one hundred twenty-three thousand, six hundred forty".