21140402191 has 2 divisors, whose sum is σ = 21140402192. Its totient is φ = 21140402190.

The previous prime is 21140402161. The next prime is 21140402209. The reversal of 21140402191 is 19120404112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21140402191 - 2¹⁵ = 21140369423 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21140402111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10570201095 + 10570201096.

It is an arithmetic number, because the mean of its divisors is an integer number (10570201096).

Almost surely, 2^21140402191 is an apocalyptic number.

21140402191 is a deficient number, since it is larger than the sum of its proper divisors (1).

21140402191 is an equidigital number, since it uses as much as digits as its factorization.

21140402191 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 25.

It can be divided in two parts, 211404021 and 91, that added together give a palindrome (211404112).

The spelling of 21140402191 in words is "twenty-one billion, one hundred forty million, four hundred two thousand, one hundred ninety-one".