1231122021161 has 2 divisors, whose sum is σ = 1231122021162. Its totient is φ = 1231122021160.

The previous prime is 1231122021149. The next prime is 1231122021251. The reversal of 1231122021161 is 1611202211321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1030135681936 + 200986339225 = 1014956^2 + 448315^2 .

It is a cyclic number.

It is not a de Polignac number, because 1231122021161 - 2⁶ = 1231122021097 is a prime.

It is a super-2 number, since 2×1231122021161² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1231122021061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 615561010580 + 615561010581.

It is an arithmetic number, because the mean of its divisors is an integer number (615561010581).

Almost surely, 2^{1231122021161} is an apocalyptic number.

It is an amenable number.

1231122021161 is a deficient number, since it is larger than the sum of its proper divisors (1).

1231122021161 is an equidigital number, since it uses as much as digits as its factorization.

1231122021161 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 23.

Adding to 1231122021161 its reverse (1611202211321), we get a palindrome (2842324232482).

The spelling of 1231122021161 in words is "one trillion, two hundred thirty-one billion, one hundred twenty-two million, twenty-one thousand, one hundred sixty-one".