91228076692921 has 9 divisors (see below), whose sum is σ = 106122534336399. Its totient is φ = 78195437000184.

The previous prime is 91228076692913. The next prime is 91228076692999. The reversal of 91228076692921 is 12929667082219.

It is a happy number.

The square root of 91228076692921 is 9551339.

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., 82676920509225 + 8551156183696 = 9092685^2 + 2924236^2 .

It is not a de Polignac number, because 91228076692921 - 2³ = 91228076692913 is a prime.

It is not an unprimeable number, because it can be changed into a prime (91228076692421) 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, 66177135 + ... + 67541611.

Almost surely, 2^{91228076692921} is an apocalyptic number.

91228076692921 is the 9551339-th square number.

91228076692921 is the 4775670-th centered octagonal number.

It is an amenable number.

91228076692921 is a deficient number, since it is larger than the sum of its proper divisors (14894457643478).

91228076692921 is an frugal number, since it uses more digits than its factorization.

91228076692921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2728968 (or 1364484 counting only the distinct ones).

The product of its (nonzero) digits is 23514624, while the sum is 64.

The spelling of 91228076692921 in words is "ninety-one trillion, two hundred twenty-eight billion, seventy-six million, six hundred ninety-two thousand, nine hundred twenty-one".