91722193081 has 4 divisors (see below), whose sum is σ = 93673729152. Its totient is φ = 89770657012.

The previous prime is 91722193037. The next prime is 91722193117. The reversal of 91722193081 is 18039122719.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91722193081 is a prime.

It is a super-2 number, since 2×91722193081² (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 (91722193181) 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, 975767965 + ... + 975768058.

It is an arithmetic number, because the mean of its divisors is an integer number (23418432288).

Almost surely, 2^91722193081 is an apocalyptic number.

It is an amenable number.

91722193081 is a deficient number, since it is larger than the sum of its proper divisors (1951536071).

91722193081 is a wasteful number, since it uses less digits than its factorization.

91722193081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1951536070.

The product of its (nonzero) digits is 54432, while the sum is 43.

The spelling of 91722193081 in words is "ninety-one billion, seven hundred twenty-two million, one hundred ninety-three thousand, eighty-one".