661237 has 2 divisors, whose sum is σ = 661238. Its totient is φ = 661236.

The previous prime is 661231. The next prime is 661253. The reversal of 661237 is 732166.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 391876 + 269361 = 626^2 + 519^2 .

It is a cyclic number.

It is not a de Polignac number, because 661237 - 2⁷ = 661109 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (661231) 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 as a sum of consecutive naturals, namely, 330618 + 330619.

It is an arithmetic number, because the mean of its divisors is an integer number (330619).

2⁶⁶¹²³⁷ is an apocalyptic number.

It is an amenable number.

661237 is a deficient number, since it is larger than the sum of its proper divisors (1).

661237 is an equidigital number, since it uses as much as digits as its factorization.

661237 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1512, while the sum is 25.

The square root of 661237 is about 813.1648049442. The cubic root of 661237 is about 87.1202371512.

It can be divided in two parts, 661 and 237, that added together give a palindrome (898).

The spelling of 661237 in words is "six hundred sixty-one thousand, two hundred thirty-seven".