91608138 has 64 divisors (see below), whose sum is σ = 218661120. Its totient is φ = 28325376.

The previous prime is 91608137. The next prime is 91608151. The reversal of 91608138 is 83180619.

It is not an unprimeable number, because it can be changed into a prime (91608133) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 66331 + ... + 67697.

It is an arithmetic number, because the mean of its divisors is an integer number (3416580).

Almost surely, 2^91608138 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91608138, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (109330560).

91608138 is an abundant number, since it is smaller than the sum of its proper divisors (127052982).

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

91608138 is a wasteful number, since it uses less digits than its factorization.

91608138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1468 (or 1462 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 36.

The square root of 91608138 is about 9571.2140295785. The cubic root of 91608138 is about 450.7938874934.

The spelling of 91608138 in words is "ninety-one million, six hundred eight thousand, one hundred thirty-eight".