21422871391 has 2 divisors, whose sum is σ = 21422871392. Its totient is φ = 21422871390.

The previous prime is 21422871359. The next prime is 21422871409. The reversal of 21422871391 is 19317822412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21422871391 - 2⁵ = 21422871359 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21422871791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10711435695 + 10711435696.

It is an arithmetic number, because the mean of its divisors is an integer number (10711435696).

Almost surely, 2^21422871391 is an apocalyptic number.

21422871391 is a deficient number, since it is larger than the sum of its proper divisors (1).

21422871391 is an equidigital number, since it uses as much as digits as its factorization.

21422871391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 48384, while the sum is 40.

The spelling of 21422871391 in words is "twenty-one billion, four hundred twenty-two million, eight hundred seventy-one thousand, three hundred ninety-one".