990412128 has 72 divisors (see below), whose sum is σ = 2825740008. Its totient is φ = 329052672.

The previous prime is 990412127. The next prime is 990412133. The reversal of 990412128 is 821214099.

It is a tau number, because it is divible by the number of its divisors (72).

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 = 990412092 and 990412101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (990412121) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 84651 + ... + 95637.

It is an arithmetic number, because the mean of its divisors is an integer number (39246389).

Almost surely, 2^990412128 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 990412128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1412870004).

990412128 is an abundant number, since it is smaller than the sum of its proper divisors (1835327880).

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

990412128 is a wasteful number, since it uses less digits than its factorization.

990412128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11316 (or 11305 counting only the distinct ones).

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

The square root of 990412128 is about 31470.8139074921. The cubic root of 990412128 is about 996.7937737666.

The spelling of 990412128 in words is "nine hundred ninety million, four hundred twelve thousand, one hundred twenty-eight".