198771840 has 128 divisors (see below), whose sum is σ = 704044800. Its totient is φ = 53001216.

The previous prime is 198771827. The next prime is 198771841. The reversal of 198771840 is 48177891.

It is a tau number, because it is divible by the number of its divisors (128).

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 (198771841) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11529 + ... + 23031.

It is an arithmetic number, because the mean of its divisors is an integer number (5500350).

Almost surely, 2^198771840 is an apocalyptic number.

198771840 is a gapful number since it is divisible by the number (10) 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 198771840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (352022400).

198771840 is an abundant number, since it is smaller than the sum of its proper divisors (505272960).

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

198771840 is a wasteful number, since it uses less digits than its factorization.

198771840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11531 (or 11513 counting only the distinct ones).

The product of its (nonzero) digits is 112896, while the sum is 45.

The square root of 198771840 is about 14098.6467435708. The cubic root of 198771840 is about 583.6040350843.

The spelling of 198771840 in words is "one hundred ninety-eight million, seven hundred seventy-one thousand, eight hundred forty".