2600530721 has 4 divisors (see below), whose sum is σ = 2603668500. Its totient is φ = 2597392944.

The previous prime is 2600530661. The next prime is 2600530747. The reversal of 2600530721 is 1270350062.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1270350062 = 2 ⋅635175031.

It can be written as a sum of positive squares in 2 ways, for example, as 1107558400 + 1492972321 = 33280^2 + 38639^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2600530721 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (2600530771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1567646 + ... + 1569303.

It is an arithmetic number, because the mean of its divisors is an integer number (650917125).

Almost surely, 2^2600530721 is an apocalyptic number.

It is an amenable number.

2600530721 is a deficient number, since it is larger than the sum of its proper divisors (3137779).

2600530721 is an equidigital number, since it uses as much as digits as its factorization.

2600530721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3137778.

The product of its (nonzero) digits is 2520, while the sum is 26.

The square root of 2600530721 is about 50995.3990179506. The cubic root of 2600530721 is about 1375.1624219812.

Adding to 2600530721 its reverse (1270350062), we get a palindrome (3870880783).

The spelling of 2600530721 in words is "two billion, six hundred million, five hundred thirty thousand, seven hundred twenty-one".