198660780 has 72 divisors (see below), whose sum is σ = 607999392. Its totient is φ = 52502016.

The previous prime is 198660779. The next prime is 198660797. The reversal of 198660780 is 87066891.

It is a happy number.

It is a super-2 number, since 2×198660780² = 78932211020416800, which contains 22 as substring.

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

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15457 + ... + 25223.

It is an arithmetic number, because the mean of its divisors is an integer number (8444436).

Almost surely, 2^198660780 is an apocalyptic number.

198660780 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 198660780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (303999696).

198660780 is an abundant number, since it is smaller than the sum of its proper divisors (409338612).

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

198660780 is a wasteful number, since it uses less digits than its factorization.

198660780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9895 (or 9890 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 45.

The square root of 198660780 is about 14094.7075173627. The cubic root of 198660780 is about 583.4953222685.

The spelling of 198660780 in words is "one hundred ninety-eight million, six hundred sixty thousand, seven hundred eighty".