199243647851 has 4 divisors (see below), whose sum is σ = 200275998552. Its totient is φ = 198211297152.

The previous prime is 199243647797. The next prime is 199243647931. The reversal of 199243647851 is 158746342991.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 199243647851 - 2⁶ = 199243647787 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (199243647151) 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, 516175061 + ... + 516175446.

It is an arithmetic number, because the mean of its divisors is an integer number (50068999638).

Almost surely, 2^199243647851 is an apocalyptic number.

199243647851 is a deficient number, since it is larger than the sum of its proper divisors (1032350701).

199243647851 is a wasteful number, since it uses less digits than its factorization.

199243647851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1032350700.

The product of its digits is 13063680, while the sum is 59.

The spelling of 199243647851 in words is "one hundred ninety-nine billion, two hundred forty-three million, six hundred forty-seven thousand, eight hundred fifty-one".