990004428 has 108 divisors (see below), whose sum is σ = 2973271392. Its totient is φ = 276816960.

The previous prime is 990004427. The next prime is 990004453. The reversal of 990004428 is 824400099.

It is a happy number.

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

It is a junction number, because it is equal to n+sod(n) for n = 990004392 and 990004401.

It is not an unprimeable number, because it can be changed into a prime (990004423) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 76938 + ... + 88878.

Almost surely, 2^990004428 is an apocalyptic number.

990004428 is a gapful number since it is divisible by the number (98) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 990004428, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1486635696).

990004428 is an abundant number, since it is smaller than the sum of its proper divisors (1983266964).

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

990004428 is a wasteful number, since it uses less digits than its factorization.

990004428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12012 (or 12000 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 990004428 is about 31464.3358105650. The cubic root of 990004428 is about 996.6569793331.

The spelling of 990004428 in words is "nine hundred ninety million, four thousand, four hundred twenty-eight".