21849127381 has 2 divisors, whose sum is σ = 21849127382. Its totient is φ = 21849127380.

The previous prime is 21849127327. The next prime is 21849127459. The reversal of 21849127381 is 18372194812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21006154225 + 842973156 = 144935^2 + 29034^2 .

It is a cyclic number.

It is not a de Polignac number, because 21849127381 - 2¹⁵ = 21849094613 is a prime.

It is a super-2 number, since 2×21849127381² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21849127301) 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, 10924563690 + 10924563691.

It is an arithmetic number, because the mean of its divisors is an integer number (10924563691).

Almost surely, 2^21849127381 is an apocalyptic number.

It is an amenable number.

21849127381 is a deficient number, since it is larger than the sum of its proper divisors (1).

21849127381 is an equidigital number, since it uses as much as digits as its factorization.

21849127381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 193536, while the sum is 46.

The spelling of 21849127381 in words is "twenty-one billion, eight hundred forty-nine million, one hundred twenty-seven thousand, three hundred eighty-one".