91819738 has 4 divisors (see below), whose sum is σ = 137729610. Its totient is φ = 45909868.

The previous prime is 91819733. The next prime is 91819759. The reversal of 91819738 is 83791819.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 83791819 = 3581 ⋅23399.

It can be written as a sum of positive squares in only one way, i.e., 86992929 + 4826809 = 9327^2 + 2197^2 .

It is not an unprimeable number, because it can be changed into a prime (91819733) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 22954933 + ... + 22954936.

Almost surely, 2^91819738 is an apocalyptic number.

91819738 is a deficient number, since it is larger than the sum of its proper divisors (45909872).

91819738 is a wasteful number, since it uses less digits than its factorization.

91819738 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45909871.

The product of its digits is 108864, while the sum is 46.

The square root of 91819738 is about 9582.2616328297. The cubic root of 91819738 is about 451.1407076164.

The spelling of 91819738 in words is "ninety-one million, eight hundred nineteen thousand, seven hundred thirty-eight".