198678657 has 8 divisors (see below), whose sum is σ = 267477184. Its totient is φ = 131166288.

The previous prime is 198678631. The next prime is 198678671. The reversal of 198678657 is 756876891.

198678657 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 198678657 - 2⁶ = 198678593 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 198678597 and 198678606.

It is not an unprimeable number, because it can be changed into a prime (198678607) 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, 321178 + ... + 321795.

It is an arithmetic number, because the mean of its divisors is an integer number (33434648).

Almost surely, 2^198678657 is an apocalyptic number.

It is an amenable number.

198678657 is a deficient number, since it is larger than the sum of its proper divisors (68798527).

198678657 is a wasteful number, since it uses less digits than its factorization.

198678657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 643079.

The product of its digits is 5080320, while the sum is 57.

The square root of 198678657 is about 14095.3416773060. The cubic root of 198678657 is about 583.5128241848.

The spelling of 198678657 in words is "one hundred ninety-eight million, six hundred seventy-eight thousand, six hundred fifty-seven".