90928991 has 2 divisors, whose sum is σ = 90928992. Its totient is φ = 90928990.

The previous prime is 90928969. The next prime is 90928997. The reversal of 90928991 is 19982909.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 90928991 - 2²⁶ = 23820127 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90928997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45464495 + 45464496.

It is an arithmetic number, because the mean of its divisors is an integer number (45464496).

Almost surely, 2^90928991 is an apocalyptic number.

90928991 is a deficient number, since it is larger than the sum of its proper divisors (1).

90928991 is an equidigital number, since it uses as much as digits as its factorization.

90928991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 104976, while the sum is 47.

The square root of 90928991 is about 9535.6694049238. The cubic root of 90928991 is about 449.6771198255.

It can be divided in two parts, 90928 and 991, that added together give a palindrome (91919).

The spelling of 90928991 in words is "ninety million, nine hundred twenty-eight thousand, nine hundred ninety-one".