199720381 has 32 divisors (see below), whose sum is σ = 246677760. Its totient is φ = 157925376.

The previous prime is 199720363. The next prime is 199720387. The reversal of 199720381 is 183027991.

It is not a de Polignac number, because 199720381 - 2⁵ = 199720349 is a prime.

It is a super-2 number, since 2×199720381² = 79776461173570322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (199720387) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1457745 + ... + 1457881.

It is an arithmetic number, because the mean of its divisors is an integer number (7708680).

Almost surely, 2^199720381 is an apocalyptic number.

It is an amenable number.

199720381 is a deficient number, since it is larger than the sum of its proper divisors (46957379).

199720381 is a wasteful number, since it uses less digits than its factorization.

199720381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 373.

The product of its (nonzero) digits is 27216, while the sum is 40.

The square root of 199720381 is about 14132.2461413605. The cubic root of 199720381 is about 584.5308835610.

The spelling of 199720381 in words is "one hundred ninety-nine million, seven hundred twenty thousand, three hundred eighty-one".