21638098943 has 2 divisors, whose sum is σ = 21638098944. Its totient is φ = 21638098942.

The previous prime is 21638098919. The next prime is 21638098957. The reversal of 21638098943 is 34989083612.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21638098943 - 2¹⁰ = 21638097919 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21638038943) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10819049471 + 10819049472.

It is an arithmetic number, because the mean of its divisors is an integer number (10819049472).

Almost surely, 2^21638098943 is an apocalyptic number.

21638098943 is a deficient number, since it is larger than the sum of its proper divisors (1).

21638098943 is an equidigital number, since it uses as much as digits as its factorization.

21638098943 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2239488, while the sum is 53.

The spelling of 21638098943 in words is "twenty-one billion, six hundred thirty-eight million, ninety-eight thousand, nine hundred forty-three".