198309640 has 32 divisors (see below), whose sum is σ = 458259480. Its totient is φ = 77179392.

The previous prime is 198309637. The next prime is 198309647. The reversal of 198309640 is 46903891.

It can be written as a sum of positive squares in 4 ways, for example, as 184036356 + 14273284 = 13566^2 + 3778^2 .

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 198309593 and 198309602.

It is not an unprimeable number, because it can be changed into a prime (198309647) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 65517 + ... + 68476.

Almost surely, 2^198309640 is an apocalyptic number.

198309640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

198309640 is an abundant number, since it is smaller than the sum of its proper divisors (259949840).

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

198309640 is a wasteful number, since it uses less digits than its factorization.

198309640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134041 (or 134037 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 40.

The square root of 198309640 is about 14082.2455595690. The cubic root of 198309640 is about 583.1513366026.

The spelling of 198309640 in words is "one hundred ninety-eight million, three hundred nine thousand, six hundred forty".