661843 has 12 divisors (see below), whose sum is σ = 829920. Its totient is φ = 523152.

The previous prime is 661823. The next prime is 661849. The reversal of 661843 is 348166.

It is not a de Polignac number, because 661843 - 2¹³ = 653651 is a prime.

It is not an unprimeable number, because it can be changed into a prime (661849) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 118 + ... + 1156.

It is an arithmetic number, because the mean of its divisors is an integer number (69160).

2⁶⁶¹⁸⁴³ is an apocalyptic number.

661843 is a deficient number, since it is larger than the sum of its proper divisors (168077).

661843 is a wasteful number, since it uses less digits than its factorization.

661843 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1066 (or 1059 counting only the distinct ones).

The product of its digits is 3456, while the sum is 28.

The square root of 661843 is about 813.5373378033. The cubic root of 661843 is about 87.1468432161.

The spelling of 661843 in words is "six hundred sixty-one thousand, eight hundred forty-three".