198487681 has 6 divisors (see below), whose sum is σ = 230893890. Its totient is φ = 170132256.

The previous prime is 198487673. The next prime is 198487697. The reversal of 198487681 is 186784891.

It is a happy number.

198487681 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 174477681 + 24010000 = 13209^2 + 4900^2 .

It is not a de Polignac number, because 198487681 - 2³ = 198487673 is a prime.

It is a super-2 number, since 2×198487681² = 78794719017515522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (198487651) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2025336 + ... + 2025433.

It is an arithmetic number, because the mean of its divisors is an integer number (38482315).

Almost surely, 2^198487681 is an apocalyptic number.

It is an amenable number.

198487681 is a deficient number, since it is larger than the sum of its proper divisors (32406209).

198487681 is an equidigital number, since it uses as much as digits as its factorization.

198487681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4050783 (or 4050776 counting only the distinct ones).

The product of its digits is 774144, while the sum is 52.

The square root of 198487681 is about 14088.5656118712. The cubic root of 198487681 is about 583.3258007916.

The spelling of 198487681 in words is "one hundred ninety-eight million, four hundred eighty-seven thousand, six hundred eighty-one".