661229 has 6 divisors (see below), whose sum is σ = 688590. Its totient is φ = 634200.

The previous prime is 661217. The next prime is 661231. The reversal of 661229 is 922166.

It can be written as a sum of positive squares in only one way, i.e., 570025 + 91204 = 755^2 + 302^2 .

It is not a de Polignac number, because 661229 - 2⁸ = 660973 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 661198 and 661207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661259) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4304 + ... + 4454.

It is an arithmetic number, because the mean of its divisors is an integer number (114765).

2⁶⁶¹²²⁹ is an apocalyptic number.

It is an amenable number.

661229 is a deficient number, since it is larger than the sum of its proper divisors (27361).

661229 is an equidigital number, since it uses as much as digits as its factorization.

661229 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 331 (or 180 counting only the distinct ones).

The product of its digits is 1296, while the sum is 26.

The square root of 661229 is about 813.1598858773. The cubic root of 661229 is about 87.1198858073.

The spelling of 661229 in words is "six hundred sixty-one thousand, two hundred twenty-nine".