218722 has 16 divisors (see below), whose sum is σ = 397440. Its totient is φ = 88128.

The previous prime is 218719. The next prime is 218723. The reversal of 218722 is 227812.

218722 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 218693 and 218702.

It is not an unprimeable number, because it can be changed into a prime (218723) 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, 222 + ... + 697.

It is an arithmetic number, because the mean of its divisors is an integer number (24840).

2²¹⁸⁷²² is an apocalyptic number.

218722 is a deficient number, since it is larger than the sum of its proper divisors (178718).

218722 is a wasteful number, since it uses less digits than its factorization.

218722 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 945.

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

The square root of 218722 is about 467.6772391297. The cubic root of 218722 is about 60.2509856763.

It can be divided in two parts, 2187 and 22, that added together give a square (2209 = 47²).

The spelling of 218722 in words is "two hundred eighteen thousand, seven hundred twenty-two".