9991404 has 48 divisors (see below), whose sum is σ = 26288640. Its totient is φ = 3281040.

The previous prime is 9991379. The next prime is 9991409. The reversal of 9991404 is 4041999.

9991404 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is a super-3 number, since 3×9991404³ (a number of 22 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (9991409) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7017 + ... + 8319.

It is an arithmetic number, because the mean of its divisors is an integer number (547680).

Almost surely, 2^9991404 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 9991404, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13144320).

9991404 is an abundant number, since it is smaller than the sum of its proper divisors (16297236).

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

9991404 is a wasteful number, since it uses less digits than its factorization.

9991404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1387 (or 1379 counting only the distinct ones).

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

The square root of 9991404 is about 3160.9182210238. The cubic root of 9991404 is about 215.3817195712.

The spelling of 9991404 in words is "nine million, nine hundred ninety-one thousand, four hundred four".