91138027879 has 2 divisors, whose sum is σ = 91138027880. Its totient is φ = 91138027878.

The previous prime is 91138027847. The next prime is 91138027927. The reversal of 91138027879 is 97872083119.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 91138027879 - 2⁵ = 91138027847 is a prime.

It is a super-2 number, since 2×91138027879² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91138027829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45569013939 + 45569013940.

It is an arithmetic number, because the mean of its divisors is an integer number (45569013940).

Almost surely, 2^91138027879 is an apocalyptic number.

91138027879 is a deficient number, since it is larger than the sum of its proper divisors (1).

91138027879 is an equidigital number, since it uses as much as digits as its factorization.

91138027879 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1524096, while the sum is 55.

The spelling of 91138027879 in words is "ninety-one billion, one hundred thirty-eight million, twenty-seven thousand, eight hundred seventy-nine".