91444882121 has 4 divisors (see below), whose sum is σ = 96823992852. Its totient is φ = 86065771392.

The previous prime is 91444882103. The next prime is 91444882141. The reversal of 91444882121 is 12128844419.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 84378630400 + 7066251721 = 290480^2 + 84061^2 .

It is a cyclic number.

It is not a de Polignac number, because 91444882121 - 2³⁴ = 74265012937 is a prime.

It is a super-2 number, since 2×91444882121² (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 (91444882141) 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, 2689555340 + ... + 2689555373.

It is an arithmetic number, because the mean of its divisors is an integer number (24205998213).

Almost surely, 2^91444882121 is an apocalyptic number.

It is an amenable number.

91444882121 is a deficient number, since it is larger than the sum of its proper divisors (5379110731).

91444882121 is a wasteful number, since it uses less digits than its factorization.

91444882121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5379110730.

The product of its digits is 147456, while the sum is 44.

The spelling of 91444882121 in words is "ninety-one billion, four hundred forty-four million, eight hundred eighty-two thousand, one hundred twenty-one".