199351621 has 4 divisors (see below), whose sum is σ = 227830432. Its totient is φ = 170872812.

The previous prime is 199351609. The next prime is 199351643. The reversal of 199351621 is 126153991.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 199351621 - 2⁹ = 199351109 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (199351661) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14239395 + ... + 14239408.

It is an arithmetic number, because the mean of its divisors is an integer number (56957608).

Almost surely, 2^199351621 is an apocalyptic number.

It is an amenable number.

199351621 is a deficient number, since it is larger than the sum of its proper divisors (28478811).

199351621 is an equidigital number, since it uses as much as digits as its factorization.

199351621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28478810.

The product of its digits is 14580, while the sum is 37.

The square root of 199351621 is about 14119.1933551460. The cubic root of 199351621 is about 584.1709062646.

The spelling of 199351621 in words is "one hundred ninety-nine million, three hundred fifty-one thousand, six hundred twenty-one".