391112141211221 has 2 divisors, whose sum is σ = 391112141211222. Its totient is φ = 391112141211220.

The previous prime is 391112141211119. The next prime is 391112141211247. The reversal of 391112141211221 is 122112141211193.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 336730941052900 + 54381200158321 = 18350230^2 + 7374361^2 .

It is a cyclic number.

It is not a de Polignac number, because 391112141211221 - 2²² = 391112137016917 is a prime.

It is a super-2 number, since 2×391112141211221² (a number of 30 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (391112141217221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 195556070605610 + 195556070605611.

It is an arithmetic number, because the mean of its divisors is an integer number (195556070605611).

Almost surely, 2^{391112141211221} is an apocalyptic number.

It is an amenable number.

391112141211221 is a deficient number, since it is larger than the sum of its proper divisors (1).

391112141211221 is an equidigital number, since it uses as much as digits as its factorization.

391112141211221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1728, while the sum is 32.

The spelling of 391112141211221 in words is "three hundred ninety-one trillion, one hundred twelve billion, one hundred forty-one million, two hundred eleven thousand, two hundred twenty-one".