998917920 has 1080 divisors, whose sum is σ = 4854356892. Its totient is φ = 191600640.

The previous prime is 998917889. The next prime is 998917937. The reversal of 998917920 is 29719899.

It can be written as a sum of positive squares in 2 ways, for example, as 929762064 + 69155856 = 30492^2 + 8316^2 .

It is a tau number, because it is divible by the number of its divisors (1080).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

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 179 ways as a sum of consecutive naturals, for example, 76839834 + ... + 76839846.

Almost surely, 2^998917920 is an apocalyptic number.

998917920 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 998917920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2427178446).

998917920 is an abundant number, since it is smaller than the sum of its proper divisors (3855438972).

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

998917920 is a wasteful number, since it uses less digits than its factorization.

998917920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76 (or 41 counting only the distinct ones).

The product of its (nonzero) digits is 734832, while the sum is 54.

The square root of 998917920 is about 31605.6627837481. The cubic root of 998917920 is about 999.6391764887.

The spelling of 998917920 in words is "nine hundred ninety-eight million, nine hundred seventeen thousand, nine hundred twenty".