2021581444 has 9 divisors (see below), whose sum is σ = 3537924901. Its totient is φ = 1010745760.

The previous prime is 2021581427. The next prime is 2021581477. The reversal of 2021581444 is 4441851202.

The square root of 2021581444 is 44962.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 78535044 + 1943046400 = 8862^2 + 44080^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 78684 + ... + 101164.

Almost surely, 2^2021581444 is an apocalyptic number.

2021581444 is the 44962-nd square number.

It is an amenable number.

2021581444 is a deficient number, since it is larger than the sum of its proper divisors (1516343457).

2021581444 is an frugal number, since it uses more digits than its factorization.

2021581444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44966 (or 22483 counting only the distinct ones).

The product of its (nonzero) digits is 10240, while the sum is 31.

The cubic root of 2021581444 is about 1264.4366656464.

The spelling of 2021581444 in words is "two billion, twenty-one million, five hundred eighty-one thousand, four hundred forty-four".