1011221161 has 2 divisors, whose sum is σ = 1011221162. Its totient is φ = 1011221160.

The previous prime is 1011221129. The next prime is 1011221207. The reversal of 1011221161 is 1611221101.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 516425625 + 494795536 = 22725^2 + 22244^2 .

It is a cyclic number.

It is not a de Polignac number, because 1011221161 - 2⁵ = 1011221129 is a prime.

It is not a weakly prime, because it can be changed into another prime (1011221111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 505610580 + 505610581.

It is an arithmetic number, because the mean of its divisors is an integer number (505610581).

Almost surely, 2^1011221161 is an apocalyptic number.

It is an amenable number.

1011221161 is a deficient number, since it is larger than the sum of its proper divisors (1).

1011221161 is an equidigital number, since it uses as much as digits as its factorization.

1011221161 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24, while the sum is 16.

The square root of 1011221161 is about 31799.7037879286. The cubic root of 1011221161 is about 1003.7264830744.

Adding to 1011221161 its reverse (1611221101), we get a palindrome (2622442262).

The spelling of 1011221161 in words is "one billion, eleven million, two hundred twenty-one thousand, one hundred sixty-one".