91573340881 has 4 divisors (see below), whose sum is σ = 99898190064. Its totient is φ = 83248491700.

The previous prime is 91573340839. The next prime is 91573340941. The reversal of 91573340881 is 18804337519.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 91573340881 - 2¹³ = 91573332689 is a prime.

It is a super-2 number, since 2×91573340881² (a number of 23 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91573340981) 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, 4162424575 + ... + 4162424596.

It is an arithmetic number, because the mean of its divisors is an integer number (24974547516).

Almost surely, 2^91573340881 is an apocalyptic number.

It is an amenable number.

91573340881 is a deficient number, since it is larger than the sum of its proper divisors (8324849183).

91573340881 is a wasteful number, since it uses less digits than its factorization.

91573340881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8324849182.

The product of its (nonzero) digits is 725760, while the sum is 49.

The spelling of 91573340881 in words is "ninety-one billion, five hundred seventy-three million, three hundred forty thousand, eight hundred eighty-one".