1221131131201 has 2 divisors, whose sum is σ = 1221131131202. Its totient is φ = 1221131131200.

The previous prime is 1221131131183. The next prime is 1221131131211. The reversal of 1221131131201 is 1021311311221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 902786922801 + 318344208400 = 950151^2 + 564220^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221131131201 - 2⁵ = 1221131131169 is a prime.

It is a super-2 number, since 2×1221131131201² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1221131131211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610565565600 + 610565565601.

It is an arithmetic number, because the mean of its divisors is an integer number (610565565601).

Almost surely, 2^{1221131131201} is an apocalyptic number.

It is an amenable number.

1221131131201 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221131131201 is an equidigital number, since it uses as much as digits as its factorization.

1221131131201 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72, while the sum is 19.

Adding to 1221131131201 its reverse (1021311311221), we get a palindrome (2242442442422).

The spelling of 1221131131201 in words is "one trillion, two hundred twenty-one billion, one hundred thirty-one million, one hundred thirty-one thousand, two hundred one".