199701981 has 12 divisors (see below), whose sum is σ = 288903420. Its totient is φ = 132929280.

The previous prime is 199701979. The next prime is 199701991. The reversal of 199701981 is 189107991.

It can be written as a sum of positive squares in 2 ways, for example, as 78481881 + 121220100 = 8859^2 + 11010^2 .

It is not a de Polignac number, because 199701981 - 2¹ = 199701979 is a prime.

It is a super-2 number, since 2×199701981² = 79761762430648722, which contains 22 as substring.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (199701991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10836 + ... + 22733.

It is an arithmetic number, because the mean of its divisors is an integer number (24075285).

Almost surely, 2^199701981 is an apocalyptic number.

It is an amenable number.

199701981 is a deficient number, since it is larger than the sum of its proper divisors (89201439).

199701981 is a wasteful number, since it uses less digits than its factorization.

199701981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34236 (or 34233 counting only the distinct ones).

The product of its (nonzero) digits is 40824, while the sum is 45.

The square root of 199701981 is about 14131.5951328928. The cubic root of 199701981 is about 584.5129322991.

The spelling of 199701981 in words is "one hundred ninety-nine million, seven hundred one thousand, nine hundred eighty-one".