2019120021 has 32 divisors (see below), whose sum is σ = 3151749120. Its totient is φ = 1275013872.

The previous prime is 2019120011. The next prime is 2019120023. The reversal of 2019120021 is 1200219102.

It is not a de Polignac number, because 2019120021 - 2¹⁴ = 2019103637 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2019119976 and 2019120003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2019120023) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 48180 + ... + 79746.

It is an arithmetic number, because the mean of its divisors is an integer number (98492160).

Almost surely, 2^2019120021 is an apocalyptic number.

It is an amenable number.

2019120021 is a deficient number, since it is larger than the sum of its proper divisors (1132629099).

2019120021 is a wasteful number, since it uses less digits than its factorization.

2019120021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31702 (or 31696 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

The square root of 2019120021 is about 44934.6194041966. The cubic root of 2019120021 is about 1263.9232759087.

Adding to 2019120021 its reverse (1200219102), we get a palindrome (3219339123).

The spelling of 2019120021 in words is "two billion, nineteen million, one hundred twenty thousand, twenty-one".