91247039 has 4 divisors (see below), whose sum is σ = 98266056. Its totient is φ = 84228024.

The previous prime is 91247011. The next prime is 91247047. The reversal of 91247039 is 93074219.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 93074219 = 7 ⋅13296317.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91247039 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 (91247059) 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, 3509489 + ... + 3509514.

It is an arithmetic number, because the mean of its divisors is an integer number (24566514).

Almost surely, 2^91247039 is an apocalyptic number.

91247039 is a deficient number, since it is larger than the sum of its proper divisors (7019017).

91247039 is a wasteful number, since it uses less digits than its factorization.

91247039 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7019016.

The product of its (nonzero) digits is 13608, while the sum is 35.

The square root of 91247039 is about 9552.3316001906. The cubic root of 91247039 is about 450.2007976302.

The spelling of 91247039 in words is "ninety-one million, two hundred forty-seven thousand, thirty-nine".