21402430342991 has 2 divisors, whose sum is σ = 21402430342992. Its totient is φ = 21402430342990.

The previous prime is 21402430342961. The next prime is 21402430343057. The reversal of 21402430342991 is 19924303420412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21402430342991 - 2⁶ = 21402430342927 is a prime.

It is a super-3 number, since 3×21402430342991³ (a number of 41 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21402430342961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10701215171495 + 10701215171496.

It is an arithmetic number, because the mean of its divisors is an integer number (10701215171496).

Almost surely, 2^{21402430342991} is an apocalyptic number.

21402430342991 is a deficient number, since it is larger than the sum of its proper divisors (1).

21402430342991 is an equidigital number, since it uses as much as digits as its factorization.

21402430342991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 373248, while the sum is 44.

The spelling of 21402430342991 in words is "twenty-one trillion, four hundred two billion, four hundred thirty million, three hundred forty-two thousand, nine hundred ninety-one".