91531797 has 16 divisors (see below), whose sum is σ = 146818560. Its totient is φ = 49550832.

The previous prime is 91531771. The next prime is 91531837. The reversal of 91531797 is 79713519.

It is not a de Polignac number, because 91531797 - 2⁷ = 91531669 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91531897) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 114303 + ... + 115100.

It is an arithmetic number, because the mean of its divisors is an integer number (9176160).

Almost surely, 2^91531797 is an apocalyptic number.

It is an amenable number.

91531797 is a deficient number, since it is larger than the sum of its proper divisors (55286763).

91531797 is a wasteful number, since it uses less digits than its factorization.

91531797 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 229432.

The product of its digits is 59535, while the sum is 42.

The square root of 91531797 is about 9567.2251463003. The cubic root of 91531797 is about 450.6686307170.

The spelling of 91531797 in words is "ninety-one million, five hundred thirty-one thousand, seven hundred ninety-seven".