2528847721 has 2 divisors, whose sum is σ = 2528847722. Its totient is φ = 2528847720.

The previous prime is 2528847707. The next prime is 2528847757. The reversal of 2528847721 is 1277488252.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1322049600 + 1206798121 = 36360^2 + 34739^2 .

It is a cyclic number.

It is not a de Polignac number, because 2528847721 - 2⁷ = 2528847593 is a prime.

It is not a weakly prime, because it can be changed into another prime (2528847701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1264423860 + 1264423861.

It is an arithmetic number, because the mean of its divisors is an integer number (1264423861).

Almost surely, 2^2528847721 is an apocalyptic number.

It is an amenable number.

2528847721 is a deficient number, since it is larger than the sum of its proper divisors (1).

2528847721 is an equidigital number, since it uses as much as digits as its factorization.

2528847721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 501760, while the sum is 46.

The square root of 2528847721 is about 50287.6497860061. The cubic root of 2528847721 is about 1362.4091742727.

The spelling of 2528847721 in words is "two billion, five hundred twenty-eight million, eight hundred forty-seven thousand, seven hundred twenty-one".