7421528112721 has 2 divisors, whose sum is σ = 7421528112722. Its totient is φ = 7421528112720.

The previous prime is 7421528112709. The next prime is 7421528112727. The reversal of 7421528112721 is 1272118251247.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7340653284496 + 80874828225 = 2709364^2 + 284385^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7421528112721 is a prime.

It is not a weakly prime, because it can be changed into another prime (7421528112727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3710764056360 + 3710764056361.

It is an arithmetic number, because the mean of its divisors is an integer number (3710764056361).

Almost surely, 2^{7421528112721} is an apocalyptic number.

It is an amenable number.

7421528112721 is a deficient number, since it is larger than the sum of its proper divisors (1).

7421528112721 is an equidigital number, since it uses as much as digits as its factorization.

7421528112721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 125440, while the sum is 43.

The spelling of 7421528112721 in words is "seven trillion, four hundred twenty-one billion, five hundred twenty-eight million, one hundred twelve thousand, seven hundred twenty-one".