221011201261 has 2 divisors, whose sum is σ = 221011201262. Its totient is φ = 221011201260.

The previous prime is 221011201247. The next prime is 221011201273. The reversal of 221011201261 is 162102110122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 219029616036 + 1981585225 = 468006^2 + 44515^2 .

It is a cyclic number.

It is not a de Polignac number, because 221011201261 - 2⁷ = 221011201133 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221011201661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110505600630 + 110505600631.

It is an arithmetic number, because the mean of its divisors is an integer number (110505600631).

Almost surely, 2^221011201261 is an apocalyptic number.

It is an amenable number.

221011201261 is a deficient number, since it is larger than the sum of its proper divisors (1).

221011201261 is an equidigital number, since it uses as much as digits as its factorization.

221011201261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96, while the sum is 19.

Adding to 221011201261 its reverse (162102110122), we get a palindrome (383113311383).

The spelling of 221011201261 in words is "two hundred twenty-one billion, eleven million, two hundred one thousand, two hundred sixty-one".