91405736231521 has 32 divisors (see below), whose sum is σ = 95866036738560. Its totient is φ = 87092557344000.

The previous prime is 91405736231507. The next prime is 91405736231549. The reversal of 91405736231521 is 12513263750419.

It is a cyclic number.

It is not a de Polignac number, because 91405736231521 - 2⁷ = 91405736231393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91405736231921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 67108155 + ... + 68456671.

It is an arithmetic number, because the mean of its divisors is an integer number (2995813648080).

Almost surely, 2^{91405736231521} is an apocalyptic number.

It is an amenable number.

91405736231521 is a deficient number, since it is larger than the sum of its proper divisors (4460300507039).

91405736231521 is a wasteful number, since it uses less digits than its factorization.

91405736231521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1348905.

The product of its (nonzero) digits is 1360800, while the sum is 49.

The spelling of 91405736231521 in words is "ninety-one trillion, four hundred five billion, seven hundred thirty-six million, two hundred thirty-one thousand, five hundred twenty-one".