91356981647 has 8 divisors (see below), whose sum is σ = 91832887152. Its totient is φ = 90881481600.

The previous prime is 91356981643. The next prime is 91356981701. The reversal of 91356981647 is 74618965319.

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 91356981647 - 2² = 91356981643 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 (91356981643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 355793 + ... + 556149.

It is an arithmetic number, because the mean of its divisors is an integer number (11479110894).

Almost surely, 2^91356981647 is an apocalyptic number.

91356981647 is a deficient number, since it is larger than the sum of its proper divisors (475905505).

91356981647 is a wasteful number, since it uses less digits than its factorization.

91356981647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 202729.

The product of its digits is 9797760, while the sum is 59.

The spelling of 91356981647 in words is "ninety-one billion, three hundred fifty-six million, nine hundred eighty-one thousand, six hundred forty-seven".