91404664993 has 4 divisors (see below), whose sum is σ = 93634047108. Its totient is φ = 89175282880.

The previous prime is 91404664961. The next prime is 91404665003. The reversal of 91404664993 is 39946640419.

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

It can be written as a sum of positive squares in 2 ways, for example, as 46804293649 + 44600371344 = 216343^2 + 211188^2 .

It is a cyclic number.

It is not a de Polignac number, because 91404664993 - 2⁵ = 91404664961 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91404664943) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1114690996 + ... + 1114691077.

It is an arithmetic number, because the mean of its divisors is an integer number (23408511777).

Almost surely, 2^91404664993 is an apocalyptic number.

It is an amenable number.

91404664993 is a deficient number, since it is larger than the sum of its proper divisors (2229382115).

91404664993 is a wasteful number, since it uses less digits than its factorization.

91404664993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2229382114.

The product of its (nonzero) digits is 5038848, while the sum is 55.

The spelling of 91404664993 in words is "ninety-one billion, four hundred four million, six hundred sixty-four thousand, nine hundred ninety-three".