21943421085479 has 2 divisors, whose sum is σ = 21943421085480. Its totient is φ = 21943421085478.

The previous prime is 21943421085403. The next prime is 21943421085529. The reversal of 21943421085479 is 97458012434912.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21943421085479 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21943421085379) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10971710542739 + 10971710542740.

It is an arithmetic number, because the mean of its divisors is an integer number (10971710542740).

Almost surely, 2^{21943421085479} is an apocalyptic number.

21943421085479 is a deficient number, since it is larger than the sum of its proper divisors (1).

21943421085479 is an equidigital number, since it uses as much as digits as its factorization.

21943421085479 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 17418240, while the sum is 59.

The spelling of 21943421085479 in words is "twenty-one trillion, nine hundred forty-three billion, four hundred twenty-one million, eighty-five thousand, four hundred seventy-nine".