91506289073 has 4 divisors (see below), whose sum is σ = 91507305828. Its totient is φ = 91505272320.

The previous prime is 91506289003. The next prime is 91506289109. The reversal of 91506289073 is 37098260519.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 37098260519 = 61223 ⋅605953.

It can be written as a sum of positive squares in 2 ways, for example, as 71348820544 + 20157468529 = 267112^2 + 141977^2 .

It is a cyclic number.

It is not a de Polignac number, because 91506289073 - 2³⁴ = 74326419889 is a prime.

It is a super-2 number, since 2×91506289073² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91506289003) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 358688 + ... + 558273.

It is an arithmetic number, because the mean of its divisors is an integer number (22876826457).

Almost surely, 2^91506289073 is an apocalyptic number.

It is an amenable number.

91506289073 is a deficient number, since it is larger than the sum of its proper divisors (1016755).

91506289073 is an equidigital number, since it uses as much as digits as its factorization.

91506289073 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1016754.

The product of its (nonzero) digits is 816480, while the sum is 50.

The spelling of 91506289073 in words is "ninety-one billion, five hundred six million, two hundred eighty-nine thousand, seventy-three".