91491081 has 8 divisors (see below), whose sum is σ = 133077984. Its totient is φ = 55449120.

The previous prime is 91491073. The next prime is 91491083. The reversal of 91491081 is 18019419.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 91491081 - 2³ = 91491073 is a prime.

It is a super-2 number, since 2×91491081² = 16741235805097122, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33), and also a Moran number because the ratio is a prime number: 2772457 = 91491081 / (9 + 1 + 4 + 9 + 1 + 0 + 8 + 1).

It is not an unprimeable number, because it can be changed into a prime (91491083) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1386196 + ... + 1386261.

It is an arithmetic number, because the mean of its divisors is an integer number (16634748).

Almost surely, 2^91491081 is an apocalyptic number.

It is an amenable number.

91491081 is a deficient number, since it is larger than the sum of its proper divisors (41586903).

91491081 is a wasteful number, since it uses less digits than its factorization.

91491081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2772471.

The product of its (nonzero) digits is 2592, while the sum is 33.

The square root of 91491081 is about 9565.0970198948. The cubic root of 91491081 is about 450.6017973104.

The spelling of 91491081 in words is "ninety-one million, four hundred ninety-one thousand, eighty-one".