998522640 has 200 divisors, whose sum is σ = 3488610048. Its totient is φ = 264695040.

The previous prime is 998522627. The next prime is 998522647. The reversal of 998522640 is 46225899.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (998522647) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 1444695 + ... + 1445385.

Almost surely, 2^998522640 is an apocalyptic number.

998522640 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 998522640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1744305024).

998522640 is an abundant number, since it is smaller than the sum of its proper divisors (2490087408).

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

998522640 is a wasteful number, since it uses less digits than its factorization.

With its successor (998522641) it forms a Ruth-Aaron pair, since the sum of their distinct prime factors is the same (924).

998522640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 939 (or 924 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 45.

The square root of 998522640 is about 31599.4088552302. The cubic root of 998522640 is about 999.5073039571.

The spelling of 998522640 in words is "nine hundred ninety-eight million, five hundred twenty-two thousand, six hundred forty".