21853459939 has 2 divisors, whose sum is σ = 21853459940. Its totient is φ = 21853459938.

The previous prime is 21853459891. The next prime is 21853459967. The reversal of 21853459939 is 93995435812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21853459939 - 2¹⁷ = 21853328867 is a prime.

It is a super-2 number, since 2×21853459939² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21853454939) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10926729969 + 10926729970.

It is an arithmetic number, because the mean of its divisors is an integer number (10926729970).

Almost surely, 2^21853459939 is an apocalyptic number.

21853459939 is a deficient number, since it is larger than the sum of its proper divisors (1).

21853459939 is an equidigital number, since it uses as much as digits as its factorization.

21853459939 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10497600, while the sum is 58.

The spelling of 21853459939 in words is "twenty-one billion, eight hundred fifty-three million, four hundred fifty-nine thousand, nine hundred thirty-nine".