2166440 has 32 divisors (see below), whose sum is σ = 4997160. Its totient is φ = 844800.

The previous prime is 2166431. The next prime is 2166449. The reversal of 2166440 is 446612.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (2166431) and next prime (2166449).

It can be written as a sum of positive squares in 4 ways, for example, as 1684804 + 481636 = 1298^2 + 694^2 .

It is a Smith number, since the sum of its digits (23) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (2166449) 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, 980 + ... + 2300.

2^2166440 is an apocalyptic number.

2166440 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 2166440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2498580).

2166440 is an abundant number, since it is smaller than the sum of its proper divisors (2830720).

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

2166440 is a wasteful number, since it uses less digits than its factorization.

2166440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1373 (or 1369 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 2166440 is about 1471.8831475358. The cubic root of 2166440 is about 129.3944220805.

The spelling of 2166440 in words is "two million, one hundred sixty-six thousand, four hundred forty".