661417 has 2 divisors, whose sum is σ = 661418. Its totient is φ = 661416.

The previous prime is 661393. The next prime is 661421. The reversal of 661417 is 714166.

It is a happy number.

661417 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 379456 + 281961 = 616^2 + 531^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-661417 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 661391 and 661400.

It is not a weakly prime, because it can be changed into another prime (661477) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330708 + 330709.

It is an arithmetic number, because the mean of its divisors is an integer number (330709).

2⁶⁶¹⁴¹⁷ is an apocalyptic number.

It is an amenable number.

661417 is a deficient number, since it is larger than the sum of its proper divisors (1).

661417 is an equidigital number, since it uses as much as digits as its factorization.

661417 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1008, while the sum is 25.

The square root of 661417 is about 813.2754760842. The cubic root of 661417 is about 87.1281416393.

The spelling of 661417 in words is "six hundred sixty-one thousand, four hundred seventeen".