21305424401879 has 2 divisors, whose sum is σ = 21305424401880. Its totient is φ = 21305424401878.

The previous prime is 21305424401803. The next prime is 21305424401881. The reversal of 21305424401879 is 97810442450312.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21305424401879 is a prime.

It is a super-2 number, since 2×21305424401879² (a number of 27 digits) contains 22 as substring.

Together with 21305424401881, 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 (21305424401279) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10652712200939 + 10652712200940.

It is an arithmetic number, because the mean of its divisors is an integer number (10652712200940).

Almost surely, 2^{21305424401879} is an apocalyptic number.

21305424401879 is a deficient number, since it is larger than the sum of its proper divisors (1).

21305424401879 is an equidigital number, since it uses as much as digits as its factorization.

21305424401879 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1935360, while the sum is 50.

The spelling of 21305424401879 in words is "twenty-one trillion, three hundred five billion, four hundred twenty-four million, four hundred one thousand, eight hundred seventy-nine".