21143907439 has 2 divisors, whose sum is σ = 21143907440. Its totient is φ = 21143907438.

The previous prime is 21143907401. The next prime is 21143907481. The reversal of 21143907439 is 93470934112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21143907439 - 2⁷ = 21143907311 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21143907395 and 21143907404.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21143907739) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10571953719 + 10571953720.

It is an arithmetic number, because the mean of its divisors is an integer number (10571953720).

Almost surely, 2^21143907439 is an apocalyptic number.

21143907439 is a deficient number, since it is larger than the sum of its proper divisors (1).

21143907439 is an equidigital number, since it uses as much as digits as its factorization.

21143907439 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 163296, while the sum is 43.

The spelling of 21143907439 in words is "twenty-one billion, one hundred forty-three million, nine hundred seven thousand, four hundred thirty-nine".