4975721521 has 2 divisors, whose sum is σ = 4975721522. Its totient is φ = 4975721520.

The previous prime is 4975721519. The next prime is 4975721561. The reversal of 4975721521 is 1251275794.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4971801121 + 3920400 = 70511^2 + 1980^2 .

It is a cyclic number.

It is not a de Polignac number, because 4975721521 - 2¹ = 4975721519 is a prime.

Together with 4975721519, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (4975721561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2487860760 + 2487860761.

It is an arithmetic number, because the mean of its divisors is an integer number (2487860761).

Almost surely, 2^4975721521 is an apocalyptic number.

It is an amenable number.

4975721521 is a deficient number, since it is larger than the sum of its proper divisors (1).

4975721521 is an equidigital number, since it uses as much as digits as its factorization.

4975721521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 176400, while the sum is 43.

The square root of 4975721521 is about 70538.7944396557. The cubic root of 4975721521 is about 1707.2037471633.

The spelling of 4975721521 in words is "four billion, nine hundred seventy-five million, seven hundred twenty-one thousand, five hundred twenty-one".