2021604281 has 4 divisors (see below), whose sum is σ = 2059747812. Its totient is φ = 1983460752.

The previous prime is 2021604259. The next prime is 2021604289. The reversal of 2021604281 is 1824061202.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 648160681 + 1373443600 = 25459^2 + 37060^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2021604281 is a prime.

It is a super-2 number, since 2×2021604281² = 8173767737915053922, which contains 22 as substring.

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 2021604281.

It is not an unprimeable number, because it can be changed into a prime (2021604289) 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, 19071686 + ... + 19071791.

It is an arithmetic number, because the mean of its divisors is an integer number (514936953).

Almost surely, 2^2021604281 is an apocalyptic number.

It is an amenable number.

2021604281 is a deficient number, since it is larger than the sum of its proper divisors (38143531).

2021604281 is an equidigital number, since it uses as much as digits as its factorization.

2021604281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38143530.

The product of its (nonzero) digits is 1536, while the sum is 26.

The square root of 2021604281 is about 44962.2539581814. The cubic root of 2021604281 is about 1264.4414269076.

Adding to 2021604281 its reverse (1824061202), we get a palindrome (3845665483).

The spelling of 2021604281 in words is "two billion, twenty-one million, six hundred four thousand, two hundred eighty-one".