122215561 has 6 divisors (see below), whose sum is σ = 132340110. Its totient is φ = 112814208.

The previous prime is 122215553. The next prime is 122215573. The reversal of 122215561 is 165512221.

It can be written as a sum of positive squares in 3 ways, for example, as 4080400 + 118135161 = 2020^2 + 10869^2 .

It is not a de Polignac number, because 122215561 - 2³ = 122215553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (122215501) 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 in 5 ways as a sum of consecutive naturals, for example, 361416 + ... + 361753.

It is an arithmetic number, because the mean of its divisors is an integer number (22056685).

Almost surely, 2^122215561 is an apocalyptic number.

It is an amenable number.

122215561 is a deficient number, since it is larger than the sum of its proper divisors (10124549).

122215561 is an equidigital number, since it uses as much as digits as its factorization.

122215561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 723195 (or 723182 counting only the distinct ones).

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

The square root of 122215561 is about 11055.1146986361. The cubic root of 122215561 is about 496.2595017924.

Adding to 122215561 its reverse (165512221), we get a palindrome (287727782).

The spelling of 122215561 in words is "one hundred twenty-two million, two hundred fifteen thousand, five hundred sixty-one".