1661072317 has 2 divisors, whose sum is σ = 1661072318. Its totient is φ = 1661072316.

The previous prime is 1661072299. The next prime is 1661072333. The reversal of 1661072317 is 7132701661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 996412356 + 664659961 = 31566^2 + 25781^2 .

It is an emirp because it is prime and its reverse (7132701661) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1661072317 is a prime.

It is a super-2 number, since 2×1661072317² = 5518322484607496978, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1661072617) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 830536158 + 830536159.

It is an arithmetic number, because the mean of its divisors is an integer number (830536159).

Almost surely, 2^1661072317 is an apocalyptic number.

It is an amenable number.

1661072317 is a deficient number, since it is larger than the sum of its proper divisors (1).

1661072317 is an equidigital number, since it uses as much as digits as its factorization.

1661072317 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10584, while the sum is 34.

The square root of 1661072317 is about 40756.2549432599. The cubic root of 1661072317 is about 1184.3030474753.

Adding to 1661072317 its reverse (7132701661), we get a palindrome (8793773978).

The spelling of 1661072317 in words is "one billion, six hundred sixty-one million, seventy-two thousand, three hundred seventeen".