199998761 has 8 divisors (see below), whose sum is σ = 219066120. Its totient is φ = 181742848.

The previous prime is 199998751. The next prime is 199998791. The reversal of 199998761 is 167899991.

It can be written as a sum of positive squares in 4 ways, for example, as 112763161 + 87235600 = 10619^2 + 9340^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 199998761 - 2²² = 195804457 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 199998761.

It is not an unprimeable number, because it can be changed into a prime (199998751) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 202346 + ... + 203331.

It is an arithmetic number, because the mean of its divisors is an integer number (27383265).

Almost surely, 2^199998761 is an apocalyptic number.

It is an amenable number.

199998761 is a deficient number, since it is larger than the sum of its proper divisors (19067359).

199998761 is a wasteful number, since it uses less digits than its factorization.

199998761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 405723.

The product of its digits is 2204496, while the sum is 59.

The square root of 199998761 is about 14142.0918183980. The cubic root of 199998761 is about 584.8023400208.

The spelling of 199998761 in words is "one hundred ninety-nine million, nine hundred ninety-eight thousand, seven hundred sixty-one".