91471340557 has 2 divisors, whose sum is σ = 91471340558. Its totient is φ = 91471340556.

The previous prime is 91471340509. The next prime is 91471340573. The reversal of 91471340557 is 75504317419.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 91200376036 + 270964521 = 301994^2 + 16461^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91471340557 is a prime.

It is a super-2 number, since 2×91471340557² (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 (91471340507) 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, 45735670278 + 45735670279.

It is an arithmetic number, because the mean of its divisors is an integer number (45735670279).

Almost surely, 2^91471340557 is an apocalyptic number.

It is an amenable number.

91471340557 is a deficient number, since it is larger than the sum of its proper divisors (1).

91471340557 is an equidigital number, since it uses as much as digits as its factorization.

91471340557 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 529200, while the sum is 46.

The spelling of 91471340557 in words is "ninety-one billion, four hundred seventy-one million, three hundred forty thousand, five hundred fifty-seven".