91918181910 has 32 divisors (see below), whose sum is σ = 223396093440. Its totient is φ = 24201242208.

The previous prime is 91918181881. The next prime is 91918181911. The reversal of 91918181910 is 1918181919.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 91918181910.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91918181911) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19389652 + ... + 19394391.

It is an arithmetic number, because the mean of its divisors is an integer number (6981127920).

Almost surely, 2^91918181910 is an apocalyptic number.

91918181910 is an abundant number, since it is smaller than the sum of its proper divisors (131477911530).

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

91918181910 is a wasteful number, since it uses less digits than its factorization.

91918181910 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38784132.

The product of its (nonzero) digits is 46656, while the sum is 48.

The spelling of 91918181910 in words is "ninety-one billion, nine hundred eighteen million, one hundred eighty-one thousand, nine hundred ten".