91211964428 has 24 divisors (see below), whose sum is σ = 171959835600. Its totient is φ = 42083046720.

The previous prime is 91211964427. The next prime is 91211964499. The reversal of 91211964428 is 82446911219.

It is not an unprimeable number, because it can be changed into a prime (91211964427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 157778 + ... + 455321.

It is an arithmetic number, because the mean of its divisors is an integer number (7164993150).

Almost surely, 2^91211964428 is an apocalyptic number.

It is an amenable number.

91211964428 is a deficient number, since it is larger than the sum of its proper divisors (80747871172).

91211964428 is a wasteful number, since it uses less digits than its factorization.

91211964428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 615977 (or 615975 counting only the distinct ones).

The product of its digits is 248832, while the sum is 47.

The spelling of 91211964428 in words is "ninety-one billion, two hundred eleven million, nine hundred sixty-four thousand, four hundred twenty-eight".