91691542 has 4 divisors (see below), whose sum is σ = 137537316. Its totient is φ = 45845770.

The previous prime is 91691519. The next prime is 91691543. The reversal of 91691542 is 24519619.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 24519619 = 269 ⋅91151.

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 as a sum of consecutive naturals, namely, 22922884 + ... + 22922887.

It is an arithmetic number, because the mean of its divisors is an integer number (34384329).

Almost surely, 2^91691542 is an apocalyptic number.

91691542 is a deficient number, since it is larger than the sum of its proper divisors (45845774).

91691542 is a wasteful number, since it uses less digits than its factorization.

91691542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45845773.

The product of its digits is 19440, while the sum is 37.

The square root of 91691542 is about 9575.5700613593. The cubic root of 91691542 is about 450.9306533954.

The spelling of 91691542 in words is "ninety-one million, six hundred ninety-one thousand, five hundred forty-two".