198636401 has 2 divisors, whose sum is σ = 198636402. Its totient is φ = 198636400.

The previous prime is 198636391. The next prime is 198636407. The reversal of 198636401 is 104636891.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 149426176 + 49210225 = 12224^2 + 7015^2 .

It is an emirp because it is prime and its reverse (104636891) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 198636401 - 2²² = 194442097 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (198636407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99318200 + 99318201.

It is an arithmetic number, because the mean of its divisors is an integer number (99318201).

Almost surely, 2^198636401 is an apocalyptic number.

It is an amenable number.

198636401 is a deficient number, since it is larger than the sum of its proper divisors (1).

198636401 is an equidigital number, since it uses as much as digits as its factorization.

198636401 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31104, while the sum is 38.

The square root of 198636401 is about 14093.8426626666. The cubic root of 198636401 is about 583.4714530807.

The spelling of 198636401 in words is "one hundred ninety-eight million, six hundred thirty-six thousand, four hundred one".