2681337721 has 4 divisors (see below), whose sum is σ = 2746736244. Its totient is φ = 2615939200.

The previous prime is 2681337707. The next prime is 2681337727. The reversal of 2681337721 is 1277331862.

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 1264869225 + 1416468496 = 35565^2 + 37636^2 .

It is a cyclic number.

It is not a de Polignac number, because 2681337721 - 2¹⁹ = 2680813433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2681337727) 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, 32699200 + ... + 32699281.

It is an arithmetic number, because the mean of its divisors is an integer number (686684061).

Almost surely, 2^2681337721 is an apocalyptic number.

It is an amenable number.

2681337721 is a deficient number, since it is larger than the sum of its proper divisors (65398523).

2681337721 is an equidigital number, since it uses as much as digits as its factorization.

2681337721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65398522.

The product of its digits is 84672, while the sum is 40.

The square root of 2681337721 is about 51781.6349780499. The cubic root of 2681337721 is about 1389.2609844182.

The spelling of 2681337721 in words is "two billion, six hundred eighty-one million, three hundred thirty-seven thousand, seven hundred twenty-one".