990872100 has 108 divisors (see below), whose sum is σ = 3164586516. Its totient is φ = 259234560.

The previous prime is 990872041. The next prime is 990872101. The reversal of 990872100 is 1278099.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 55980324 + 934891776 = 7482^2 + 30576^2 .

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (990872101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 37314 + ... + 58086.

It is an arithmetic number, because the mean of its divisors is an integer number (29301727).

Almost surely, 2^990872100 is an apocalyptic number.

990872100 is a gapful number since it is divisible by the number (90) 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 990872100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1582293258).

990872100 is an abundant number, since it is smaller than the sum of its proper divisors (2173714416).

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

990872100 is a wasteful number, since it uses less digits than its factorization.

990872100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20846 (or 20836 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 36.

The square root of 990872100 is about 31478.1209731458. The cubic root of 990872100 is about 996.9480618156.

The spelling of 990872100 in words is "nine hundred ninety million, eight hundred seventy-two thousand, one hundred".