991543246847 has 32 divisors (see below), whose sum is σ = 1060947201600. Its totient is φ = 924874288128.

The previous prime is 991543246829. The next prime is 991543246861. The reversal of 991543246847 is 748642345199.

It is not a de Polignac number, because 991543246847 - 2⁶ = 991543246783 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 991543246847.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991543246807) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 110547779 + ... + 110556747.

It is an arithmetic number, because the mean of its divisors is an integer number (33154600050).

Almost surely, 2^991543246847 is an apocalyptic number.

991543246847 is a deficient number, since it is larger than the sum of its proper divisors (69403954753).

991543246847 is a wasteful number, since it uses less digits than its factorization.

991543246847 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9755.

The product of its digits is 52254720, while the sum is 62.

The spelling of 991543246847 in words is "nine hundred ninety-one billion, five hundred forty-three million, two hundred forty-six thousand, eight hundred forty-seven".