27591997789 has 2 divisors, whose sum is σ = 27591997790. Its totient is φ = 27591997788.

The previous prime is 27591997721. The next prime is 27591997793. The reversal of 27591997789 is 98779919572.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20928540889 + 6663456900 = 144667^2 + 81630^2 .

It is a cyclic number.

It is not a de Polignac number, because 27591997789 - 2²⁹ = 27055126877 is a prime.

It is a super-2 number, since 2×27591997789² (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 (27591997799) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13795998894 + 13795998895.

It is an arithmetic number, because the mean of its divisors is an integer number (13795998895).

Almost surely, 2^27591997789 is an apocalyptic number.

It is an amenable number.

27591997789 is a deficient number, since it is larger than the sum of its proper divisors (1).

27591997789 is an equidigital number, since it uses as much as digits as its factorization.

27591997789 is an evil number, because the sum of its binary digits is even.

The product of its digits is 180033840, while the sum is 73.

The spelling of 27591997789 in words is "twenty-seven billion, five hundred ninety-one million, nine hundred ninety-seven thousand, seven hundred eighty-nine".