661037317 has 2 divisors, whose sum is σ = 661037318. Its totient is φ = 661037316.

The previous prime is 661037291. The next prime is 661037327. The reversal of 661037317 is 713730166.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 348419556 + 312617761 = 18666^2 + 17681^2 .

It is a cyclic number.

It is not a de Polignac number, because 661037317 - 2¹⁵ = 661004549 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (661037327) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330518658 + 330518659.

It is an arithmetic number, because the mean of its divisors is an integer number (330518659).

Almost surely, 2^661037317 is an apocalyptic number.

It is an amenable number.

661037317 is a deficient number, since it is larger than the sum of its proper divisors (1).

661037317 is an equidigital number, since it uses as much as digits as its factorization.

661037317 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15876, while the sum is 34.

The square root of 661037317 is about 25710.6459856613. The cubic root of 661037317 is about 871.1146662878.

The spelling of 661037317 in words is "six hundred sixty-one million, thirty-seven thousand, three hundred seventeen".