161222515 has 16 divisors (see below), whose sum is σ = 198056160. Its totient is φ = 125984352.

The previous prime is 161222497. The next prime is 161222519. The reversal of 161222515 is 515222161.

It is not a de Polignac number, because 161222515 - 2⁹ = 161222003 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 161222515.

It is not an unprimeable number, because it can be changed into a prime (161222519) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1026817 + ... + 1026973.

It is an arithmetic number, because the mean of its divisors is an integer number (12378510).

Almost surely, 2^161222515 is an apocalyptic number.

161222515 is a deficient number, since it is larger than the sum of its proper divisors (36833645).

161222515 is an frugal number, since it uses more digits than its factorization.

161222515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 339 (or 221 counting only the distinct ones).

The product of its digits is 1200, while the sum is 25.

The square root of 161222515 is about 12697.3428322622. The cubic root of 161222515 is about 544.2626900906.

Adding to 161222515 its reverse (515222161), we get a palindrome (676444676).

The spelling of 161222515 in words is "one hundred sixty-one million, two hundred twenty-two thousand, five hundred fifteen".