199880981 has 4 divisors (see below), whose sum is σ = 202411200. Its totient is φ = 197350764.

The previous prime is 199880977. The next prime is 199880983. The reversal of 199880981 is 189088991.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 199880981 - 2² = 199880977 is a prime.

It is a super-2 number, since 2×199880981² = 79904813131044722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (199880983) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1264991 + ... + 1265148.

It is an arithmetic number, because the mean of its divisors is an integer number (50602800).

Almost surely, 2^199880981 is an apocalyptic number.

It is an amenable number.

199880981 is a deficient number, since it is larger than the sum of its proper divisors (2530219).

199880981 is an equidigital number, since it uses as much as digits as its factorization.

199880981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2530218.

The product of its (nonzero) digits is 373248, while the sum is 53.

The square root of 199880981 is about 14137.9270404115. The cubic root of 199880981 is about 584.6875200680.

The spelling of 199880981 in words is "one hundred ninety-nine million, eight hundred eighty thousand, nine hundred eighty-one".