21391281341 has 2 divisors, whose sum is σ = 21391281342. Its totient is φ = 21391281340.

The previous prime is 21391281299. The next prime is 21391281371. The reversal of 21391281341 is 14318219312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11118648025 + 10272633316 = 105445^2 + 101354^2 .

It is a cyclic number.

It is not a de Polignac number, because 21391281341 - 2⁶ = 21391281277 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21391281371) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10695640670 + 10695640671.

It is an arithmetic number, because the mean of its divisors is an integer number (10695640671).

Almost surely, 2^21391281341 is an apocalyptic number.

It is an amenable number.

21391281341 is a deficient number, since it is larger than the sum of its proper divisors (1).

21391281341 is an equidigital number, since it uses as much as digits as its factorization.

21391281341 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10368, while the sum is 35.

The spelling of 21391281341 in words is "twenty-one billion, three hundred ninety-one million, two hundred eighty-one thousand, three hundred forty-one".