21679478479 has 2 divisors, whose sum is σ = 21679478480. Its totient is φ = 21679478478.

The previous prime is 21679478449. The next prime is 21679478501. The reversal of 21679478479 is 97487497612.

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-21679478479 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21679478479.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21679478449) 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, 10839739239 + 10839739240.

It is an arithmetic number, because the mean of its divisors is an integer number (10839739240).

Almost surely, 2^21679478479 is an apocalyptic number.

21679478479 is a deficient number, since it is larger than the sum of its proper divisors (1).

21679478479 is an equidigital number, since it uses as much as digits as its factorization.

21679478479 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 42674688, while the sum is 64.

The spelling of 21679478479 in words is "twenty-one billion, six hundred seventy-nine million, four hundred seventy-eight thousand, four hundred seventy-nine".