161222717 has 4 divisors (see below), whose sum is σ = 161484636. Its totient is φ = 160960800.

The previous prime is 161222693. The next prime is 161222741. The reversal of 161222717 is 717222161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 717222161 = 193 ⋅3716177.

It is an interprime number because it is at equal distance from previous prime (161222693) and next prime (161222741).

It can be written as a sum of positive squares in 2 ways, for example, as 32649796 + 128572921 = 5714^2 + 11339^2 .

It is a cyclic number.

It is not a de Polignac number, because 161222717 - 2⁸ = 161222461 is a prime.

It is a super-3 number, since 3×161222717³ (a number of 26 digits) contains 333 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 161222717.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161222417) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 130034 + ... + 131267.

It is an arithmetic number, because the mean of its divisors is an integer number (40371159).

Almost surely, 2^161222717 is an apocalyptic number.

It is an amenable number.

161222717 is a deficient number, since it is larger than the sum of its proper divisors (261919).

161222717 is an equidigital number, since it uses as much as digits as its factorization.

161222717 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 261918.

The product of its digits is 2352, while the sum is 29.

The square root of 161222717 is about 12697.3507866799. The cubic root of 161222717 is about 544.2629173976.

Adding to 161222717 its reverse (717222161), we get a palindrome (878444878).

The spelling of 161222717 in words is "one hundred sixty-one million, two hundred twenty-two thousand, seven hundred seventeen".