2019800021 has 8 divisors (see below), whose sum is σ = 2035212480. Its totient is φ = 2004433792.

The previous prime is 2019800017. The next prime is 2019800047. The reversal of 2019800021 is 1200089102.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2019800021 - 2² = 2019800017 is a prime.

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 2019800021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2019803021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 78821 + ... + 101253.

It is an arithmetic number, because the mean of its divisors is an integer number (254401560).

Almost surely, 2^2019800021 is an apocalyptic number.

It is an amenable number.

2019800021 is a deficient number, since it is larger than the sum of its proper divisors (15412459).

2019800021 is a wasteful number, since it uses less digits than its factorization.

2019800021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23115.

The product of its (nonzero) digits is 288, while the sum is 23.

The square root of 2019800021 is about 44942.1853162483. The cubic root of 2019800021 is about 1264.0651481687.

Adding to 2019800021 its reverse (1200089102), we get a palindrome (3219889123).

The spelling of 2019800021 in words is "two billion, nineteen million, eight hundred thousand, twenty-one".