91284638 has 4 divisors (see below), whose sum is σ = 136926960. Its totient is φ = 45642318.

The previous prime is 91284593. The next prime is 91284647. The reversal of 91284638 is 83648219.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 83648219 = 2677 ⋅31247.

It is a junction number, because it is equal to n+sod(n) for n = 91284595 and 91284604.

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, 22821158 + ... + 22821161.

It is an arithmetic number, because the mean of its divisors is an integer number (34231740).

Almost surely, 2^91284638 is an apocalyptic number.

91284638 is a deficient number, since it is larger than the sum of its proper divisors (45642322).

91284638 is a wasteful number, since it uses less digits than its factorization.

91284638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45642321.

The product of its digits is 82944, while the sum is 41.

The square root of 91284638 is about 9554.2994510325. The cubic root of 91284638 is about 450.2626252998.

The spelling of 91284638 in words is "ninety-one million, two hundred eighty-four thousand, six hundred thirty-eight".