21321401191 has 2 divisors, whose sum is σ = 21321401192. Its totient is φ = 21321401190.

The previous prime is 21321401183. The next prime is 21321401221. The reversal of 21321401191 is 19110412312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21321401191 - 2³ = 21321401183 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21321404191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10660700595 + 10660700596.

It is an arithmetic number, because the mean of its divisors is an integer number (10660700596).

Almost surely, 2^21321401191 is an apocalyptic number.

21321401191 is a deficient number, since it is larger than the sum of its proper divisors (1).

21321401191 is an equidigital number, since it uses as much as digits as its factorization.

21321401191 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 25.

The spelling of 21321401191 in words is "twenty-one billion, three hundred twenty-one million, four hundred one thousand, one hundred ninety-one".