199006421 has 2 divisors, whose sum is σ = 199006422. Its totient is φ = 199006420.

The previous prime is 199006363. The next prime is 199006427. The reversal of 199006421 is 124600991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 195160900 + 3845521 = 13970^2 + 1961^2 .

It is an emirp because it is prime and its reverse (124600991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 199006421 - 2¹⁸ = 198744277 is a prime.

It is equal to p_11026895 and since 199006421 and 11026895 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199006427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99503210 + 99503211.

It is an arithmetic number, because the mean of its divisors is an integer number (99503211).

Almost surely, 2^199006421 is an apocalyptic number.

It is an amenable number.

199006421 is a deficient number, since it is larger than the sum of its proper divisors (1).

199006421 is an equidigital number, since it uses as much as digits as its factorization.

199006421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 199006421 is about 14106.9635641409. The cubic root of 199006421 is about 583.8335253350.

The spelling of 199006421 in words is "one hundred ninety-nine million, six thousand, four hundred twenty-one".