27981989831 has 2 divisors, whose sum is σ = 27981989832. Its totient is φ = 27981989830.

The previous prime is 27981989803. The next prime is 27981989839. The reversal of 27981989831 is 13898918972.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 27981989831 - 2³⁰ = 26908248007 is a prime.

It is a super-2 number, since 2×27981989831² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27981989839) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13990994915 + 13990994916.

It is an arithmetic number, because the mean of its divisors is an integer number (13990994916).

Almost surely, 2^27981989831 is an apocalyptic number.

27981989831 is a deficient number, since it is larger than the sum of its proper divisors (1).

27981989831 is an equidigital number, since it uses as much as digits as its factorization.

27981989831 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15676416, while the sum is 65.

The spelling of 27981989831 in words is "twenty-seven billion, nine hundred eighty-one million, nine hundred eighty-nine thousand, eight hundred thirty-one".