199631805 has 16 divisors (see below), whose sum is σ = 321374400. Its totient is φ = 105815808.

The previous prime is 199631791. The next prime is 199631813. The reversal of 199631805 is 508136991.

It is not a de Polignac number, because 199631805 - 2¹⁴ = 199615421 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 38380 + ... + 43269.

It is an arithmetic number, because the mean of its divisors is an integer number (20085900).

Almost surely, 2^199631805 is an apocalyptic number.

199631805 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

199631805 is a deficient number, since it is larger than the sum of its proper divisors (121742595).

199631805 is a wasteful number, since it uses less digits than its factorization.

199631805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81820.

The product of its (nonzero) digits is 58320, while the sum is 42.

The square root of 199631805 is about 14129.1119678485. Note that the first 3 decimals coincide. The cubic root of 199631805 is about 584.4444576234. Note that the first 4 decimals are identical.

The spelling of 199631805 in words is "one hundred ninety-nine million, six hundred thirty-one thousand, eight hundred five".