198640357 has 2 divisors, whose sum is σ = 198640358. Its totient is φ = 198640356.

The previous prime is 198640303. The next prime is 198640363. The reversal of 198640357 is 753046891.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 193738561 + 4901796 = 13919^2 + 2214^2 .

It is a cyclic number.

It is not a de Polignac number, because 198640357 - 2²³ = 190251749 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (198644357) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99320178 + 99320179.

It is an arithmetic number, because the mean of its divisors is an integer number (99320179).

Almost surely, 2^198640357 is an apocalyptic number.

It is an amenable number.

198640357 is a deficient number, since it is larger than the sum of its proper divisors (1).

198640357 is an equidigital number, since it uses as much as digits as its factorization.

198640357 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 181440, while the sum is 43.

The square root of 198640357 is about 14093.9830069431. The cubic root of 198640357 is about 583.4753264858.

The spelling of 198640357 in words is "one hundred ninety-eight million, six hundred forty thousand, three hundred fifty-seven".