2172640 has 48 divisors (see below), whose sum is σ = 5285952. Its totient is φ = 843264.

The previous prime is 2172619. The next prime is 2172641. The reversal of 2172640 is 462712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2172641) 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, 5737 + ... + 6103.

It is an arithmetic number, because the mean of its divisors is an integer number (110124).

2^2172640 is an apocalyptic number.

2172640 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 2172640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2642976).

2172640 is an abundant number, since it is smaller than the sum of its proper divisors (3113312).

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

2172640 is a wasteful number, since it uses less digits than its factorization.

2172640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 419 (or 411 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 22.

The square root of 2172640 is about 1473.9877882805. The cubic root of 2172640 is about 129.5177398018.

The spelling of 2172640 in words is "two million, one hundred seventy-two thousand, six hundred forty".