661822 has 16 divisors (see below), whose sum is σ = 1163232. Its totient is φ = 276480.

The previous prime is 661777. The next prime is 661823. The reversal of 661822 is 228166.

661822 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661823) by changing a digit.

661822 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3 + ... + 1150.

It is an arithmetic number, because the mean of its divisors is an integer number (72702).

2⁶⁶¹⁸²² is an apocalyptic number.

661822 is a deficient number, since it is larger than the sum of its proper divisors (501410).

661822 is a wasteful number, since it uses less digits than its factorization.

661822 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1203.

The product of its digits is 1152, while the sum is 25.

The square root of 661822 is about 813.5244311021. The cubic root of 661822 is about 87.1459214955.

Adding to 661822 its reverse (228166), we get a palindrome (889988).

The spelling of 661822 in words is "six hundred sixty-one thousand, eight hundred twenty-two".