91281811 has 2 divisors, whose sum is σ = 91281812. Its totient is φ = 91281810.

The previous prime is 91281809. The next prime is 91281829. The reversal of 91281811 is 11818219.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 91281811 - 2¹ = 91281809 is a prime.

Together with 91281809, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (91281851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45640905 + 45640906.

It is an arithmetic number, because the mean of its divisors is an integer number (45640906).

Almost surely, 2^91281811 is an apocalyptic number.

91281811 is a deficient number, since it is larger than the sum of its proper divisors (1).

91281811 is an equidigital number, since it uses as much as digits as its factorization.

91281811 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1152, while the sum is 31.

The square root of 91281811 is about 9554.1515060208. The cubic root of 91281811 is about 450.2579771808.

The spelling of 91281811 in words is "ninety-one million, two hundred eighty-one thousand, eight hundred eleven".