199621081 has 12 divisors (see below), whose sum is σ = 219769200. Its totient is φ = 181183640.

The previous prime is 199621069. The next prime is 199621091. The reversal of 199621081 is 180126991.

It is not a de Polignac number, because 199621081 - 2²⁷ = 65403353 is a prime.

It is a super-2 number, since 2×199621081² = 79697151959217122, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 199621081.

It is not an unprimeable number, because it can be changed into a prime (199621001) 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, 122490 + ... + 124108.

It is an arithmetic number, because the mean of its divisors is an integer number (18314100).

Almost surely, 2^199621081 is an apocalyptic number.

199621081 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

199621081 is a deficient number, since it is larger than the sum of its proper divisors (20148119).

199621081 is a wasteful number, since it uses less digits than its factorization.

199621081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2660 (or 2649 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 37.

The square root of 199621081 is about 14128.7324626097. The cubic root of 199621081 is about 584.4339921991.

The spelling of 199621081 in words is "one hundred ninety-nine million, six hundred twenty-one thousand, eighty-one".