91288307021 has 16 divisors (see below), whose sum is σ = 100876886784. Its totient is φ = 82169666304.

The previous prime is 91288306973. The next prime is 91288307051. The reversal of 91288307021 is 12070388219.

It is a cyclic number.

It is not a de Polignac number, because 91288307021 - 2³⁰ = 90214565197 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 91288307021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91288307051) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3084731 + ... + 3114183.

It is an arithmetic number, because the mean of its divisors is an integer number (6304805424).

Almost surely, 2^91288307021 is an apocalyptic number.

It is an amenable number.

91288307021 is a deficient number, since it is larger than the sum of its proper divisors (9588579763).

91288307021 is a wasteful number, since it uses less digits than its factorization.

91288307021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37420.

The product of its (nonzero) digits is 48384, while the sum is 41.

The spelling of 91288307021 in words is "ninety-one billion, two hundred eighty-eight million, three hundred seven thousand, twenty-one".