2172720 has 80 divisors (see below), whose sum is σ = 7356672. Its totient is φ = 526080.

The previous prime is 2172701. The next prime is 2172721. The reversal of 2172720 is 272712.

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (2172721) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2229 + ... + 3051.

2^2172720 is an apocalyptic number.

2172720 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 2172720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3678336).

2172720 is an abundant number, since it is smaller than the sum of its proper divisors (5183952).

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

2172720 is a wasteful number, since it uses less digits than its factorization.

2172720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 850 (or 844 counting only the distinct ones).

The product of its (nonzero) digits is 392, while the sum is 21.

The square root of 2172720 is about 1474.0149252976. The cubic root of 2172720 is about 129.5193294641.

The spelling of 2172720 in words is "two million, one hundred seventy-two thousand, seven hundred twenty".