2217820 has 48 divisors (see below), whose sum is σ = 5388768. Its totient is φ = 757760.

The previous prime is 2217799. The next prime is 2217829. The reversal of 2217820 is 287122.

2217820 = T₁₇ + T₁₈ + ... + T₂₃₆.

2217820 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a junction number, because it is equal to n+sod(n) for n = 2217791 and 2217800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2217829) 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, 3444 + ... + 4036.

It is an arithmetic number, because the mean of its divisors is an integer number (112266).

2^2217820 is an apocalyptic number.

2217820 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 2217820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2694384).

2217820 is an abundant number, since it is smaller than the sum of its proper divisors (3170948).

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

2217820 is a wasteful number, since it uses less digits than its factorization.

2217820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 630 (or 628 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 22.

The square root of 2217820 is about 1489.2347027920. The cubic root of 2217820 is about 130.4093604883.

The spelling of 2217820 in words is "two million, two hundred seventeen thousand, eight hundred twenty".