199447721801 has 2 divisors, whose sum is σ = 199447721802. Its totient is φ = 199447721800.

The previous prime is 199447721797. The next prime is 199447721833. The reversal of 199447721801 is 108127744991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 199430123776 + 17598025 = 446576^2 + 4195^2 .

It is a cyclic number.

It is not a de Polignac number, because 199447721801 - 2² = 199447721797 is a prime.

It is not a weakly prime, because it can be changed into another prime (199447729801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99723860900 + 99723860901.

It is an arithmetic number, because the mean of its divisors is an integer number (99723860901).

Almost surely, 2^199447721801 is an apocalyptic number.

It is an amenable number.

199447721801 is a deficient number, since it is larger than the sum of its proper divisors (1).

199447721801 is an equidigital number, since it uses as much as digits as its factorization.

199447721801 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1016064, while the sum is 53.

The spelling of 199447721801 in words is "one hundred ninety-nine billion, four hundred forty-seven million, seven hundred twenty-one thousand, eight hundred one".