21873638447 has 2 divisors, whose sum is σ = 21873638448. Its totient is φ = 21873638446.

The previous prime is 21873638417. The next prime is 21873638453. The reversal of 21873638447 is 74483637812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21873638447 - 2¹⁶ = 21873572911 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21873638407) 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, 10936819223 + 10936819224.

It is an arithmetic number, because the mean of its divisors is an integer number (10936819224).

Almost surely, 2^21873638447 is an apocalyptic number.

21873638447 is a deficient number, since it is larger than the sum of its proper divisors (1).

21873638447 is an equidigital number, since it uses as much as digits as its factorization.

21873638447 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5419008, while the sum is 53.

The spelling of 21873638447 in words is "twenty-one billion, eight hundred seventy-three million, six hundred thirty-eight thousand, four hundred forty-seven".