990477840 has 160 divisors (see below), whose sum is σ = 3406924800. Its totient is φ = 236008960.

The previous prime is 990477821. The next prime is 990477881. The reversal of 990477840 is 48774099.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 990477840.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 152581 + ... + 158939.

It is an arithmetic number, because the mean of its divisors is an integer number (21293280).

Almost surely, 2^990477840 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 990477840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1703462400).

990477840 is an abundant number, since it is smaller than the sum of its proper divisors (2416446960).

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

990477840 is a wasteful number, since it uses less digits than its factorization.

990477840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6445 (or 6439 counting only the distinct ones).

The product of its (nonzero) digits is 508032, while the sum is 48.

The square root of 990477840 is about 31471.8579051190. The cubic root of 990477840 is about 996.8158184158.

The spelling of 990477840 in words is "nine hundred ninety million, four hundred seventy-seven thousand, eight hundred forty".