1220005161 has 6 divisors (see below), whose sum is σ = 1762229690. Its totient is φ = 813336768.

The previous prime is 1220005151. The next prime is 1220005183. The reversal of 1220005161 is 1615000221.

1220005161 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 1119303936 + 100701225 = 33456^2 + 10035^2 .

It is not a de Polignac number, because 1220005161 - 2⁶ = 1220005097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1220005151) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 67778056 + ... + 67778073.

Almost surely, 2^1220005161 is an apocalyptic number.

It is an amenable number.

1220005161 is a deficient number, since it is larger than the sum of its proper divisors (542224529).

1220005161 is a wasteful number, since it uses less digits than its factorization.

1220005161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135556135 (or 135556132 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 18.

The square root of 1220005161 is about 34928.5722725679. The cubic root of 1220005161 is about 1068.5312368905.

Adding to 1220005161 its reverse (1615000221), we get a palindrome (2835005382).

The spelling of 1220005161 in words is "one billion, two hundred twenty million, five thousand, one hundred sixty-one".