1999445381 has 4 divisors (see below), whose sum is σ = 1999627392. Its totient is φ = 1999263372.

The previous prime is 1999445369. The next prime is 1999445387. The reversal of 1999445381 is 1835449991.

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 a de Polignac number, because none of the positive numbers 2^k-1999445381 is a prime.

It is a super-2 number, since 2×1999445381² = 7995563663204470322, 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 (1999445387) 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 3 ways as a sum of consecutive naturals, for example, 73391 + ... + 96876.

It is an arithmetic number, because the mean of its divisors is an integer number (499906848).

Almost surely, 2^1999445381 is an apocalyptic number.

It is an amenable number.

1999445381 is a deficient number, since it is larger than the sum of its proper divisors (182011).

1999445381 is a wasteful number, since it uses less digits than its factorization.

1999445381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 182010.

The product of its digits is 1399680, while the sum is 53.

The square root of 1999445381 is about 44715.1582911209. The cubic root of 1999445381 is about 1259.8045764357.

The spelling of 1999445381 in words is "one billion, nine hundred ninety-nine million, four hundred forty-five thousand, three hundred eighty-one".