661393 has 2 divisors, whose sum is σ = 661394. Its totient is φ = 661392.

The previous prime is 661373. The next prime is 661417. The reversal of 661393 is 393166.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 506944 + 154449 = 712^2 + 393^2 .

It is a cyclic number.

It is not a de Polignac number, because 661393 - 2⁵ = 661361 is a prime.

It is equal to p₅₃₆₇₇ and since 661393 and 53677 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (661343) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330696 + 330697.

It is an arithmetic number, because the mean of its divisors is an integer number (330697).

2⁶⁶¹³⁹³ is an apocalyptic number.

It is an amenable number.

661393 is a deficient number, since it is larger than the sum of its proper divisors (1).

661393 is an equidigital number, since it uses as much as digits as its factorization.

661393 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2916, while the sum is 28.

The square root of 661393 is about 813.2607208024. The cubic root of 661393 is about 87.1270877904.

The spelling of 661393 in words is "six hundred sixty-one thousand, three hundred ninety-three".