2019728891 has 4 divisors (see below), whose sum is σ = 2037602712. Its totient is φ = 2001855072.

The previous prime is 2019728873. The next prime is 2019728959. The reversal of 2019728891 is 1988279102.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2019728891 - 2⁶ = 2019728827 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2019728801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8936741 + ... + 8936966.

It is an arithmetic number, because the mean of its divisors is an integer number (509400678).

Almost surely, 2^2019728891 is an apocalyptic number.

2019728891 is a deficient number, since it is larger than the sum of its proper divisors (17873821).

2019728891 is a wasteful number, since it uses less digits than its factorization.

2019728891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17873820.

The product of its (nonzero) digits is 145152, while the sum is 47.

The square root of 2019728891 is about 44941.3939592443. The cubic root of 2019728891 is about 1264.0503094043.

The spelling of 2019728891 in words is "two billion, nineteen million, seven hundred twenty-eight thousand, eight hundred ninety-one".