91387438 has 4 divisors (see below), whose sum is σ = 137081160. Its totient is φ = 45693718.

The previous prime is 91387421. The next prime is 91387463. The reversal of 91387438 is 83478319.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 83478319 = 31 ⋅2692849.

It is a junction number, because it is equal to n+sod(n) for n = 91387394 and 91387403.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 22846858 + ... + 22846861.

It is an arithmetic number, because the mean of its divisors is an integer number (34270290).

Almost surely, 2^91387438 is an apocalyptic number.

91387438 is a deficient number, since it is larger than the sum of its proper divisors (45693722).

91387438 is a wasteful number, since it uses less digits than its factorization.

91387438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45693721.

The product of its digits is 145152, while the sum is 43.

The square root of 91387438 is about 9559.6777142328. The cubic root of 91387438 is about 450.4315826564.

The spelling of 91387438 in words is "ninety-one million, three hundred eighty-seven thousand, four hundred thirty-eight".