21030402191 has 2 divisors, whose sum is σ = 21030402192. Its totient is φ = 21030402190.

The previous prime is 21030402181. The next prime is 21030402193. The reversal of 21030402191 is 19120403012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21030402191 - 2²⁶ = 20963293327 is a prime.

Together with 21030402193, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21030402193) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10515201095 + 10515201096.

It is an arithmetic number, because the mean of its divisors is an integer number (10515201096).

Almost surely, 2^21030402191 is an apocalyptic number.

21030402191 is a deficient number, since it is larger than the sum of its proper divisors (1).

21030402191 is an equidigital number, since it uses as much as digits as its factorization.

21030402191 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 23.

The spelling of 21030402191 in words is "twenty-one billion, thirty million, four hundred two thousand, one hundred ninety-one".