91691541 has 8 divisors (see below), whose sum is σ = 135839360. Its totient is φ = 61127676.

The previous prime is 91691519. The next prime is 91691543. The reversal of 91691541 is 14519619.

It is not a de Polignac number, because 91691541 - 2⁹ = 91691029 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 91691496 and 91691505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91691543) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1697965 + ... + 1698018.

It is an arithmetic number, because the mean of its divisors is an integer number (16979920).

Almost surely, 2^91691541 is an apocalyptic number.

It is an amenable number.

91691541 is a deficient number, since it is larger than the sum of its proper divisors (44147819).

91691541 is a wasteful number, since it uses less digits than its factorization.

91691541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3395992 (or 3395986 counting only the distinct ones).

The product of its digits is 9720, while the sum is 36.

The square root of 91691541 is about 9575.5700091431. The cubic root of 91691541 is about 450.9306517561.

The spelling of 91691541 in words is "ninety-one million, six hundred ninety-one thousand, five hundred forty-one".