91128998914801 has 9 divisors (see below), whose sum is σ = 96177888341451. Its totient is φ = 86332563983304.

The previous prime is 91128998914783. The next prime is 91128998914841. The reversal of 91128998914801 is 10841989982119.

The square root of 91128998914801 is 9546151.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 61942424863201 + 29186574051600 = 7870351^2 + 5402460^2 .

It is not a de Polignac number, because 91128998914801 - 2⁷ = 91128998914673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91128998914841) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 181125655 + ... + 181628083.

It is an arithmetic number, because the mean of its divisors is an integer number (10686432037939).

Almost surely, 2^{91128998914801} is an apocalyptic number.

91128998914801 is the 9546151-st square number.

91128998914801 is the 4773076-th centered octagonal number.

It is an amenable number.

91128998914801 is a deficient number, since it is larger than the sum of its proper divisors (5048889426650).

91128998914801 is an frugal number, since it uses more digits than its factorization.

91128998914801 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1004896 (or 502448 counting only the distinct ones).

The product of its (nonzero) digits is 26873856, while the sum is 70.

The spelling of 91128998914801 in words is "ninety-one trillion, one hundred twenty-eight billion, nine hundred ninety-eight million, nine hundred fourteen thousand, eight hundred one".