91247681 has 8 divisors (see below), whose sum is σ = 104364864. Its totient is φ = 78150960.

The previous prime is 91247641. The next prime is 91247683. The reversal of 91247681 is 18674219.

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 91247681 - 2¹⁸ = 90985537 is a prime.

It is a super-2 number, since 2×91247681² = 16652278575755522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91247683) 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, 6086 + ... + 14816.

It is an arithmetic number, because the mean of its divisors is an integer number (13045608).

Almost surely, 2^91247681 is an apocalyptic number.

It is an amenable number.

91247681 is a deficient number, since it is larger than the sum of its proper divisors (13117183).

91247681 is a wasteful number, since it uses less digits than its factorization.

91247681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10231.

The product of its digits is 24192, while the sum is 38.

The square root of 91247681 is about 9552.3652044926. The cubic root of 91247681 is about 450.2018534753.

The spelling of 91247681 in words is "ninety-one million, two hundred forty-seven thousand, six hundred eighty-one".