9901638 has 24 divisors (see below), whose sum is σ = 22387248. Its totient is φ = 3156912.

The previous prime is 9901637. The next prime is 9901649. The reversal of 9901638 is 8361099.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9901637) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11545 + ... + 12372.

It is an arithmetic number, because the mean of its divisors is an integer number (932802).

Almost surely, 2^9901638 is an apocalyptic number.

9901638 is an abundant number, since it is smaller than the sum of its proper divisors (12485610).

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

9901638 is a wasteful number, since it uses less digits than its factorization.

9901638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23948 (or 23945 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 36.

The square root of 9901638 is about 3146.6868290314. The cubic root of 9901638 is about 214.7347585430.

It can be divided in two parts, 990 and 1638, that added together give a triangular number (2628 = T₇₂).

The spelling of 9901638 in words is "nine million, nine hundred one thousand, six hundred thirty-eight".