198642551 has 2 divisors, whose sum is σ = 198642552. Its totient is φ = 198642550.

The previous prime is 198642541. The next prime is 198642583. The reversal of 198642551 is 155246891.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 198642551 - 2⁶ = 198642487 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 198642499 and 198642508.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (198642541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99321275 + 99321276.

It is an arithmetic number, because the mean of its divisors is an integer number (99321276).

Almost surely, 2^198642551 is an apocalyptic number.

198642551 is a deficient number, since it is larger than the sum of its proper divisors (1).

198642551 is an equidigital number, since it uses as much as digits as its factorization.

198642551 is an evil number, because the sum of its binary digits is even.

The product of its digits is 86400, while the sum is 41.

The square root of 198642551 is about 14094.0608413615. The cubic root of 198642551 is about 583.4774746565.

The spelling of 198642551 in words is "one hundred ninety-eight million, six hundred forty-two thousand, five hundred fifty-one".