198421640129 has 2 divisors, whose sum is σ = 198421640130. Its totient is φ = 198421640128.

The previous prime is 198421640101. The next prime is 198421640191. The reversal of 198421640129 is 921046124891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 148903374400 + 49518265729 = 385880^2 + 222527^2 .

It is a cyclic number.

It is not a de Polignac number, because 198421640129 - 2²⁰ = 198420591553 is a prime.

It is a super-2 number, since 2×198421640129² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (198421642129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99210820064 + 99210820065.

It is an arithmetic number, because the mean of its divisors is an integer number (99210820065).

Almost surely, 2^198421640129 is an apocalyptic number.

It is an amenable number.

198421640129 is a deficient number, since it is larger than the sum of its proper divisors (1).

198421640129 is an equidigital number, since it uses as much as digits as its factorization.

198421640129 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 248832, while the sum is 47.

The spelling of 198421640129 in words is "one hundred ninety-eight billion, four hundred twenty-one million, six hundred forty thousand, one hundred twenty-nine".