198640551 has 8 divisors (see below), whose sum is σ = 269343360. Its totient is φ = 130182392.

The previous prime is 198640549. The next prime is 198640567. The reversal of 198640551 is 155046891.

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 198640551 - 2¹ = 198640549 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (198640501) 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, 560955 + ... + 561308.

It is an arithmetic number, because the mean of its divisors is an integer number (33667920).

Almost surely, 2^198640551 is an apocalyptic number.

198640551 is a deficient number, since it is larger than the sum of its proper divisors (70702809).

198640551 is a wasteful number, since it uses less digits than its factorization.

198640551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1122325.

The product of its (nonzero) digits is 43200, while the sum is 39.

The square root of 198640551 is about 14093.9898893110. The cubic root of 198640551 is about 583.4755164341.

The spelling of 198640551 in words is "one hundred ninety-eight million, six hundred forty thousand, five hundred fifty-one".