2043115721 has 4 divisors (see below), whose sum is σ = 2051884692. Its totient is φ = 2034346752.

The previous prime is 2043115703. The next prime is 2043115741. The reversal of 2043115721 is 1275113402.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1275113402 = 2 ⋅637556701.

It can be written as a sum of positive squares in 2 ways, for example, as 790734400 + 1252381321 = 28120^2 + 35389^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2043115721 is a prime.

It is a super-4 number, since 4×2043115721⁴ (a number of 38 digits) contains 4444 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2043115741) 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, 4384136 + ... + 4384601.

It is an arithmetic number, because the mean of its divisors is an integer number (512971173).

Almost surely, 2^2043115721 is an apocalyptic number.

It is an amenable number.

2043115721 is a deficient number, since it is larger than the sum of its proper divisors (8768971).

2043115721 is an equidigital number, since it uses as much as digits as its factorization.

2043115721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8768970.

The product of its (nonzero) digits is 1680, while the sum is 26.

The square root of 2043115721 is about 45200.8376139204. The cubic root of 2043115721 is about 1268.9104924301.

The spelling of 2043115721 in words is "two billion, forty-three million, one hundred fifteen thousand, seven hundred twenty-one".