91001539 has 2 divisors, whose sum is σ = 91001540. Its totient is φ = 91001538.

The previous prime is 91001489. The next prime is 91001549. The reversal of 91001539 is 93510019.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 91001539 - 2¹⁵ = 90968771 is a prime.

It is not a weakly prime, because it can be changed into another prime (91001549) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45500769 + 45500770.

It is an arithmetic number, because the mean of its divisors is an integer number (45500770).

Almost surely, 2^91001539 is an apocalyptic number.

91001539 is a deficient number, since it is larger than the sum of its proper divisors (1).

91001539 is an equidigital number, since it uses as much as digits as its factorization.

91001539 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1215, while the sum is 28.

The square root of 91001539 is about 9539.4726793466. The cubic root of 91001539 is about 449.7966801660.

The spelling of 91001539 in words is "ninety-one million, one thousand, five hundred thirty-nine".