721011541 has 2 divisors, whose sum is σ = 721011542. Its totient is φ = 721011540.

The previous prime is 721011539. The next prime is 721011553. The reversal of 721011541 is 145110127.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 705964900 + 15046641 = 26570^2 + 3879^2 .

It is a cyclic number.

It is not a de Polignac number, because 721011541 - 2¹ = 721011539 is a prime.

Together with 721011539, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (721012541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360505770 + 360505771.

It is an arithmetic number, because the mean of its divisors is an integer number (360505771).

Almost surely, 2^721011541 is an apocalyptic number.

It is an amenable number.

721011541 is a deficient number, since it is larger than the sum of its proper divisors (1).

721011541 is an equidigital number, since it uses as much as digits as its factorization.

721011541 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 280, while the sum is 22.

The square root of 721011541 is about 26851.6580679853. The cubic root of 721011541 is about 896.7004866637.

Adding to 721011541 its reverse (145110127), we get a palindrome (866121668).

The spelling of 721011541 in words is "seven hundred twenty-one million, eleven thousand, five hundred forty-one".