91138193698 has 4 divisors (see below), whose sum is σ = 136707290550. Its totient is φ = 45569096848.

The previous prime is 91138193669. The next prime is 91138193719. The reversal of 91138193698 is 89639183119.

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

It can be written as a sum of positive squares in only one way, i.e., 48798135409 + 42340058289 = 220903^2 + 205767^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 22784548423 + ... + 22784548426.

Almost surely, 2^91138193698 is an apocalyptic number.

91138193698 is a deficient number, since it is larger than the sum of its proper divisors (45569096852).

91138193698 is a wasteful number, since it uses less digits than its factorization.

91138193698 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45569096851.

The product of its digits is 2519424, while the sum is 58.

The spelling of 91138193698 in words is "ninety-one billion, one hundred thirty-eight million, one hundred ninety-three thousand, six hundred ninety-eight".