199447890787 has 4 divisors (see below), whose sum is σ = 199448926600. Its totient is φ = 199446854976.

The previous prime is 199447890757. The next prime is 199447890827. The reversal of 199447890787 is 787098744991.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 199447890787 - 2²³ = 199439502179 is a prime.

It is a super-2 number, since 2×199447890787² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (199447890727) 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 in 3 ways as a sum of consecutive naturals, for example, 134433 + ... + 645730.

It is an arithmetic number, because the mean of its divisors is an integer number (49862231650).

Almost surely, 2^199447890787 is an apocalyptic number.

199447890787 is a deficient number, since it is larger than the sum of its proper divisors (1035813).

199447890787 is an equidigital number, since it uses as much as digits as its factorization.

199447890787 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1035812.

The product of its (nonzero) digits is 256048128, while the sum is 73.

The spelling of 199447890787 in words is "one hundred ninety-nine billion, four hundred forty-seven million, eight hundred ninety thousand, seven hundred eighty-seven".