91406664018 has 12 divisors (see below), whose sum is σ = 198047772078. Its totient is φ = 30468888000.

The previous prime is 91406663987. The next prime is 91406664031. The reversal of 91406664018 is 81046660419.

It can be written as a sum of positive squares in only one way, i.e., 81107052849 + 10299611169 = 284793^2 + 101487^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2539073983 + ... + 2539074018.

Almost surely, 2^91406664018 is an apocalyptic number.

91406664018 is an abundant number, since it is smaller than the sum of its proper divisors (106641108060).

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

91406664018 is a wasteful number, since it uses less digits than its factorization.

91406664018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5078148009 (or 5078148006 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 45.

The spelling of 91406664018 in words is "ninety-one billion, four hundred six million, six hundred sixty-four thousand, eighteen".