91477173496981 has 2 divisors, whose sum is σ = 91477173496982. Its totient is φ = 91477173496980.

The previous prime is 91477173496957. The next prime is 91477173496993. The reversal of 91477173496981 is 18969437177419.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 91477173496900 + 81 = 9564370^2 + 9^2 .

It is an emirp because it is prime and its reverse (18969437177419) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91477173496981 - 2²⁷ = 91477039279253 is a prime.

It is a super-2 number, since 2×91477173496981² (a number of 29 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 91477173496898 and 91477173496907.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91477173496921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45738586748490 + 45738586748491.

It is an arithmetic number, because the mean of its divisors is an integer number (45738586748491).

Almost surely, 2^{91477173496981} is an apocalyptic number.

It is an amenable number.

91477173496981 is a deficient number, since it is larger than the sum of its proper divisors (1).

91477173496981 is an equidigital number, since it uses as much as digits as its factorization.

91477173496981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 576108288, while the sum is 76.

It can be divided in two parts, 914771734969 and 81, that multiplied together give a square (74096510532489 = 8607933²).

The spelling of 91477173496981 in words is "ninety-one trillion, four hundred seventy-seven billion, one hundred seventy-three million, four hundred ninety-six thousand, nine hundred eighty-one".