21043402279 has 2 divisors, whose sum is σ = 21043402280. Its totient is φ = 21043402278.

The previous prime is 21043402273. The next prime is 21043402283. The reversal of 21043402279 is 97220434012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21043402279 - 2²⁵ = 21009847847 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21043402273) 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, 10521701139 + 10521701140.

It is an arithmetic number, because the mean of its divisors is an integer number (10521701140).

Almost surely, 2^21043402279 is an apocalyptic number.

21043402279 is a deficient number, since it is larger than the sum of its proper divisors (1).

21043402279 is an equidigital number, since it uses as much as digits as its factorization.

21043402279 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24192, while the sum is 34.

The spelling of 21043402279 in words is "twenty-one billion, forty-three million, four hundred two thousand, two hundred seventy-nine".