1899009981 has 32 divisors (see below), whose sum is σ = 3127040640. Its totient is φ = 1129190400.

The previous prime is 1899009977. The next prime is 1899009991.

1899009981 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 1899009981 - 2² = 1899009977 is a prime.

It is a super-2 number, since 2×1899009981² = 7212477815875240722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1899009901) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 44580 + ... + 76061.

It is an arithmetic number, because the mean of its divisors is an integer number (97720020).

Almost surely, 2^1899009981 is an apocalyptic number.

1899009981 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1899009981 is a deficient number, since it is larger than the sum of its proper divisors (1228030659).

1899009981 is a wasteful number, since it uses less digits than its factorization.

1899009981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120714 (or 120708 counting only the distinct ones).

The product of its (nonzero) digits is 419904, while the sum is 54.

The square root of 1899009981 is about 43577.6316589142. The cubic root of 1899009981 is about 1238.3471694062.

The spelling of 1899009981 in words is "one billion, eight hundred ninety-nine million, nine thousand, nine hundred eighty-one".