199977798 has 16 divisors (see below), whose sum is σ = 407502576. Its totient is φ = 65401440.

The previous prime is 199977797. The next prime is 199977803. The reversal of 199977798 is 897779991.

It is a happy number.

It is a super-2 number, since 2×199977798² = 79982239385857608, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (199977797) 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 7 ways as a sum of consecutive naturals, for example, 314113 + ... + 314748.

It is an arithmetic number, because the mean of its divisors is an integer number (25468911).

Almost surely, 2^199977798 is an apocalyptic number.

199977798 is an abundant number, since it is smaller than the sum of its proper divisors (207524778).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

199977798 is a wasteful number, since it uses less digits than its factorization.

199977798 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 628919.

The product of its digits is 18003384, while the sum is 66.

The square root of 199977798 is about 14141.3506427074. The cubic root of 199977798 is about 584.7819071612.

It can be divided in two parts, 1999 and 77798, that added together give a palindrome (79797).

The spelling of 199977798 in words is "one hundred ninety-nine million, nine hundred seventy-seven thousand, seven hundred ninety-eight".