199951001 has 4 divisors (see below), whose sum is σ = 199979904. Its totient is φ = 199922100.

The previous prime is 199950977. The next prime is 199951009. The reversal of 199951001 is 100159991.

199951001 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 100159991 = 109 ⋅918899.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-199951001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (199951009) 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, 2756 + ... + 20186.

It is an arithmetic number, because the mean of its divisors is an integer number (49994976).

Almost surely, 2^199951001 is an apocalyptic number.

It is an amenable number.

199951001 is a deficient number, since it is larger than the sum of its proper divisors (28903).

199951001 is a wasteful number, since it uses less digits than its factorization.

199951001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28902.

The product of its (nonzero) digits is 3645, while the sum is 35.

The square root of 199951001 is about 14140.4031413535. The cubic root of 199951001 is about 584.7557857602.

The spelling of 199951001 in words is "one hundred ninety-nine million, nine hundred fifty-one thousand, one".