2019981 has 4 divisors (see below), whose sum is σ = 2693312. Its totient is φ = 1346652.

The previous prime is 2019977. The next prime is 2020001. The reversal of 2019981 is 1899102.

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 not a de Polignac number, because 2019981 - 2² = 2019977 is a prime.

It is a super-2 number, since 2×2019981² = 8160646480722, which contains 22 as substring.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2019911) 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, 336661 + ... + 336666.

It is an arithmetic number, because the mean of its divisors is an integer number (673328).

2^2019981 is an apocalyptic number.

It is an amenable number.

2019981 is a deficient number, since it is larger than the sum of its proper divisors (673331).

2019981 is an equidigital number, since it uses as much as digits as its factorization.

2019981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 673330.

The product of its (nonzero) digits is 1296, while the sum is 30.

The square root of 2019981 is about 1421.2603561628. The cubic root of 2019981 is about 126.4102901479.

The spelling of 2019981 in words is "two million, nineteen thousand, nine hundred eighty-one".