1212213161 has 2 divisors, whose sum is σ = 1212213162. Its totient is φ = 1212213160.

The previous prime is 1212213157. The next prime is 1212213187. The reversal of 1212213161 is 1613122121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1164174400 + 48038761 = 34120^2 + 6931^2 .

It is a cyclic number.

It is not a de Polignac number, because 1212213161 - 2² = 1212213157 is a prime.

It is a super-2 number, since 2×1212213161² = 2938921495403223842, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1212213151) 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, 606106580 + 606106581.

It is an arithmetic number, because the mean of its divisors is an integer number (606106581).

Almost surely, 2^1212213161 is an apocalyptic number.

It is an amenable number.

1212213161 is a deficient number, since it is larger than the sum of its proper divisors (1).

1212213161 is an equidigital number, since it uses as much as digits as its factorization.

1212213161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 144, while the sum is 20.

The square root of 1212213161 is about 34816.8516813339. The cubic root of 1212213161 is about 1066.2515240719.

Adding to 1212213161 its reverse (1613122121), we get a palindrome (2825335282).

The spelling of 1212213161 in words is "one billion, two hundred twelve million, two hundred thirteen thousand, one hundred sixty-one".