91228638 has 16 divisors (see below), whose sum is σ = 182572416. Its totient is φ = 30390360.

The previous prime is 91228637. The next prime is 91228639. The reversal of 91228638 is 83682219.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (91228637) and next prime (91228639).

It is a junction number, because it is equal to n+sod(n) for n = 91228596 and 91228605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91228637) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8223 + ... + 15813.

It is an arithmetic number, because the mean of its divisors is an integer number (11410776).

Almost surely, 2^91228638 is an apocalyptic number.

91228638 is an abundant number, since it is smaller than the sum of its proper divisors (91343778).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

91228638 is a wasteful number, since it uses less digits than its factorization.

91228638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9599.

The product of its digits is 41472, while the sum is 39.

The square root of 91228638 is about 9551.3683836401. The cubic root of 91228638 is about 450.1705328972.

The spelling of 91228638 in words is "ninety-one million, two hundred twenty-eight thousand, six hundred thirty-eight".