198644657 has 8 divisors (see below), whose sum is σ = 200788896. Its totient is φ = 196510752.

The previous prime is 198644623. The next prime is 198644659. The reversal of 198644657 is 756446891.

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

It is a cyclic number.

It is not a de Polignac number, because 198644657 - 2⁸ = 198644401 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (198644659) 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, 39698 + ... + 44420.

It is an arithmetic number, because the mean of its divisors is an integer number (25098612).

Almost surely, 2^198644657 is an apocalyptic number.

It is an amenable number.

198644657 is a deficient number, since it is larger than the sum of its proper divisors (2144239).

198644657 is a wasteful number, since it uses less digits than its factorization.

198644657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5167.

The product of its digits is 1451520, while the sum is 50.

The square root of 198644657 is about 14094.1355534846. The cubic root of 198644657 is about 583.4795366504.

The spelling of 198644657 in words is "one hundred ninety-eight million, six hundred forty-four thousand, six hundred fifty-seven".