91743991 has 8 divisors (see below), whose sum is σ = 93202704. Its totient is φ = 90290880.

The previous prime is 91743947. The next prime is 91744001. The reversal of 91743991 is 19934719.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 91743991 - 2⁹ = 91743479 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91743931) 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, 41781 + ... + 43921.

It is an arithmetic number, because the mean of its divisors is an integer number (11650338).

Almost surely, 2^91743991 is an apocalyptic number.

91743991 is a deficient number, since it is larger than the sum of its proper divisors (1458713).

91743991 is a wasteful number, since it uses less digits than its factorization.

91743991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2801.

The product of its digits is 61236, while the sum is 43.

The square root of 91743991 is about 9578.3083579513. The cubic root of 91743991 is about 451.0166168085.

The spelling of 91743991 in words is "ninety-one million, seven hundred forty-three thousand, nine hundred ninety-one".