4549821721 has 2 divisors, whose sum is σ = 4549821722. Its totient is φ = 4549821720.

The previous prime is 4549821713. The next prime is 4549821737. The reversal of 4549821721 is 1271289454.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4065337600 + 484484121 = 63760^2 + 22011^2 .

It is a cyclic number.

It is not a de Polignac number, because 4549821721 - 2³ = 4549821713 is a prime.

It is not a weakly prime, because it can be changed into another prime (4549821791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2274910860 + 2274910861.

It is an arithmetic number, because the mean of its divisors is an integer number (2274910861).

Almost surely, 2^4549821721 is an apocalyptic number.

It is an amenable number.

4549821721 is a deficient number, since it is larger than the sum of its proper divisors (1).

4549821721 is an equidigital number, since it uses as much as digits as its factorization.

4549821721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 161280, while the sum is 43.

The square root of 4549821721 is about 67452.3663113460. The cubic root of 4549821721 is about 1657.0341536981.

The spelling of 4549821721 in words is "four billion, five hundred forty-nine million, eight hundred twenty-one thousand, seven hundred twenty-one".