91031385 has 16 divisors (see below), whose sum is σ = 145768896. Its totient is φ = 48510528.

The previous prime is 91031383. The next prime is 91031417. The reversal of 91031385 is 58313019.

It is a happy number.

It is not a de Polignac number, because 91031385 - 2¹ = 91031383 is a prime.

It is not an unprimeable number, because it can be changed into a prime (91031383) 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, 32667 + ... + 35343.

It is an arithmetic number, because the mean of its divisors is an integer number (9110556).

Almost surely, 2^91031385 is an apocalyptic number.

It is an amenable number.

91031385 is a deficient number, since it is larger than the sum of its proper divisors (54737511).

91031385 is a wasteful number, since it uses less digits than its factorization.

91031385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4952.

The product of its (nonzero) digits is 3240, while the sum is 30.

The square root of 91031385 is about 9541.0368933361. The cubic root of 91031385 is about 449.8458484346.

The spelling of 91031385 in words is "ninety-one million, thirty-one thousand, three hundred eighty-five".