91089121 has 2 divisors, whose sum is σ = 91089122. Its totient is φ = 91089120.

The previous prime is 91089109. The next prime is 91089137. The reversal of 91089121 is 12198019.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 65028096 + 26061025 = 8064^2 + 5105^2 .

It is a cyclic number.

It is not a de Polignac number, because 91089121 - 2¹³ = 91080929 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (91089221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45544560 + 45544561.

It is an arithmetic number, because the mean of its divisors is an integer number (45544561).

Almost surely, 2^91089121 is an apocalyptic number.

It is an amenable number.

91089121 is a deficient number, since it is larger than the sum of its proper divisors (1).

91089121 is an equidigital number, since it uses as much as digits as its factorization.

91089121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 31.

The square root of 91089121 is about 9544.0620806866. The cubic root of 91089121 is about 449.9409321647.

It can be divided in two parts, 9 and 1089121, that multiplied together give a palindrome (9802089).

The spelling of 91089121 in words is "ninety-one million, eighty-nine thousand, one hundred twenty-one".