161623717 has 2 divisors, whose sum is σ = 161623718. Its totient is φ = 161623716.

The previous prime is 161623711. The next prime is 161623729. The reversal of 161623717 is 717326161.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 148620481 + 13003236 = 12191^2 + 3606^2 .

It is an emirp because it is prime and its reverse (717326161) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161623717 is a prime.

It is a super-2 number, since 2×161623717² = 52244451793792178, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161623711) 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, 80811858 + 80811859.

It is an arithmetic number, because the mean of its divisors is an integer number (80811859).

Almost surely, 2^161623717 is an apocalyptic number.

It is an amenable number.

161623717 is a deficient number, since it is larger than the sum of its proper divisors (1).

161623717 is an equidigital number, since it uses as much as digits as its factorization.

161623717 is an odious number, because the sum of its binary digits is odd.

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

The square root of 161623717 is about 12713.1316755550. The cubic root of 161623717 is about 544.7137817611.

Adding to 161623717 its reverse (717326161), we get a palindrome (878949878).

The spelling of 161623717 in words is "one hundred sixty-one million, six hundred twenty-three thousand, seven hundred seventeen".