21838849399 has 2 divisors, whose sum is σ = 21838849400. Its totient is φ = 21838849398.

The previous prime is 21838849381. The next prime is 21838849427. The reversal of 21838849399 is 99394883812.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21838849399 - 2¹³ = 21838841207 is a prime.

It is a super-2 number, since 2×21838849399² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21838849399.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21838849379) 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, 10919424699 + 10919424700.

It is an arithmetic number, because the mean of its divisors is an integer number (10919424700).

Almost surely, 2^21838849399 is an apocalyptic number.

21838849399 is a deficient number, since it is larger than the sum of its proper divisors (1).

21838849399 is an equidigital number, since it uses as much as digits as its factorization.

21838849399 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 26873856, while the sum is 64.

The spelling of 21838849399 in words is "twenty-one billion, eight hundred thirty-eight million, eight hundred forty-nine thousand, three hundred ninety-nine".