91138228644 has 48 divisors (see below), whose sum is σ = 224007940800. Its totient is φ = 28759965696.

The previous prime is 91138228619. The next prime is 91138228667. The reversal of 91138228644 is 44682283119.

It is a junction number, because it is equal to n+sod(n) for n = 91138228593 and 91138228602.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 179404 + ... + 463100.

It is an arithmetic number, because the mean of its divisors is an integer number (4666832100).

Almost surely, 2^91138228644 is an apocalyptic number.

It is an amenable number.

91138228644 is an abundant number, since it is smaller than the sum of its proper divisors (132869712156).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

91138228644 is a wasteful number, since it uses less digits than its factorization.

91138228644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 285132 (or 285130 counting only the distinct ones).

The product of its digits is 663552, while the sum is 48.

The spelling of 91138228644 in words is "ninety-one billion, one hundred thirty-eight million, two hundred twenty-eight thousand, six hundred forty-four".