91011618078 has 64 divisors (see below), whose sum is σ = 193425408000. Its totient is φ = 28467954144.

The previous prime is 91011617993. The next prime is 91011618091. The reversal of 91011618078 is 87081611019.

It is a super-2 number, since 2×91011618078² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9536233 + ... + 9545771.

It is an arithmetic number, because the mean of its divisors is an integer number (3022272000).

Almost surely, 2^91011618078 is an apocalyptic number.

91011618078 is an abundant number, since it is smaller than the sum of its proper divisors (102413789922).

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

91011618078 is a wasteful number, since it uses less digits than its factorization.

91011618078 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10349.

The product of its (nonzero) digits is 24192, while the sum is 42.

The spelling of 91011618078 in words is "ninety-one billion, eleven million, six hundred eighteen thousand, seventy-eight".