91497971 has 4 divisors (see below), whose sum is σ = 91753200. Its totient is φ = 91242744.

The previous prime is 91497949. The next prime is 91497983. The reversal of 91497971 is 17979419.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 17979419 = 151 ⋅119069.

It is a cyclic number.

It is not a de Polignac number, because 91497971 - 2⁶ = 91497907 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91497941) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 127076 + ... + 127793.

It is an arithmetic number, because the mean of its divisors is an integer number (22938300).

Almost surely, 2^91497971 is an apocalyptic number.

91497971 is a deficient number, since it is larger than the sum of its proper divisors (255229).

91497971 is a wasteful number, since it uses less digits than its factorization.

91497971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 255228.

The product of its digits is 142884, while the sum is 47.

The square root of 91497971 is about 9565.4571767376. The cubic root of 91497971 is about 450.6131083162.

The spelling of 91497971 in words is "ninety-one million, four hundred ninety-seven thousand, nine hundred seventy-one".