91778434331 has 4 divisors (see below), whose sum is σ = 91837686000. Its totient is φ = 91719182664.

The previous prime is 91778434303. The next prime is 91778434337. The reversal of 91778434331 is 13343487719.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91778434331 is a prime.

It is a super-2 number, since 2×91778434331² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 91778434331.

It is not an unprimeable number, because it can be changed into a prime (91778434337) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29623511 + ... + 29626608.

It is an arithmetic number, because the mean of its divisors is an integer number (22959421500).

Almost surely, 2^91778434331 is an apocalyptic number.

91778434331 is a deficient number, since it is larger than the sum of its proper divisors (59251669).

91778434331 is a wasteful number, since it uses less digits than its factorization.

91778434331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59251668.

The product of its digits is 1524096, while the sum is 50.

The spelling of 91778434331 in words is "ninety-one billion, seven hundred seventy-eight million, four hundred thirty-four thousand, three hundred thirty-one".