21051552439 has 2 divisors, whose sum is σ = 21051552440. Its totient is φ = 21051552438.

The previous prime is 21051552419. The next prime is 21051552497. The reversal of 21051552439 is 93425515012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21051552439 - 2¹⁷ = 21051421367 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21051552398 and 21051552407.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21051552419) 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, 10525776219 + 10525776220.

It is an arithmetic number, because the mean of its divisors is an integer number (10525776220).

Almost surely, 2^21051552439 is an apocalyptic number.

21051552439 is a deficient number, since it is larger than the sum of its proper divisors (1).

21051552439 is an equidigital number, since it uses as much as digits as its factorization.

21051552439 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 54000, while the sum is 37.

The spelling of 21051552439 in words is "twenty-one billion, fifty-one million, five hundred fifty-two thousand, four hundred thirty-nine".