661117 has 2 divisors, whose sum is σ = 661118. Its totient is φ = 661116.

The previous prime is 661109. The next prime is 661121. The reversal of 661117 is 711166.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 509796 + 151321 = 714^2 + 389^2 .

It is a cyclic number.

It is not a de Polignac number, because 661117 - 2³ = 661109 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (661187) 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, 330558 + 330559.

It is an arithmetic number, because the mean of its divisors is an integer number (330559).

2⁶⁶¹¹¹⁷ is an apocalyptic number.

It is an amenable number.

661117 is a deficient number, since it is larger than the sum of its proper divisors (1).

661117 is an equidigital number, since it uses as much as digits as its factorization.

661117 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 252, while the sum is 22.

The square root of 661117 is about 813.0910158156. The cubic root of 661117 is about 87.1149666955.

The spelling of 661117 in words is "six hundred sixty-one thousand, one hundred seventeen".