199549273421 has 2 divisors, whose sum is σ = 199549273422. Its totient is φ = 199549273420.

The previous prime is 199549273369. The next prime is 199549273439. The reversal of 199549273421 is 124372945991.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 153092212900 + 46457060521 = 391270^2 + 215539^2 .

It is a cyclic number.

It is not a de Polignac number, because 199549273421 - 2²² = 199545079117 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199549273471) 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, 99774636710 + 99774636711.

It is an arithmetic number, because the mean of its divisors is an integer number (99774636711).

Almost surely, 2^199549273421 is an apocalyptic number.

It is an amenable number.

199549273421 is a deficient number, since it is larger than the sum of its proper divisors (1).

199549273421 is an equidigital number, since it uses as much as digits as its factorization.

199549273421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4898880, while the sum is 56.

The spelling of 199549273421 in words is "one hundred ninety-nine billion, five hundred forty-nine million, two hundred seventy-three thousand, four hundred twenty-one".