91488705857 has 2 divisors, whose sum is σ = 91488705858. Its totient is φ = 91488705856.

The previous prime is 91488705793. The next prime is 91488705863. The reversal of 91488705857 is 75850788419.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 91488705841 + 16 = 302471^2 + 4^2 .

It is a cyclic number.

It is not a de Polignac number, because 91488705857 - 2⁶ = 91488705793 is a prime.

It is a super-2 number, since 2×91488705857² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 91488705857.

It is not a weakly prime, because it can be changed into another prime (91488705157) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45744352928 + 45744352929.

It is an arithmetic number, because the mean of its divisors is an integer number (45744352929).

Almost surely, 2^91488705857 is an apocalyptic number.

It is an amenable number.

91488705857 is a deficient number, since it is larger than the sum of its proper divisors (1).

91488705857 is an equidigital number, since it uses as much as digits as its factorization.

91488705857 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 22579200, while the sum is 62.

The spelling of 91488705857 in words is "ninety-one billion, four hundred eighty-eight million, seven hundred five thousand, eight hundred fifty-seven".