721011569 has 2 divisors, whose sum is σ = 721011570. Its totient is φ = 721011568.

The previous prime is 721011553. The next prime is 721011593. The reversal of 721011569 is 965110127.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 679279969 + 41731600 = 26063^2 + 6460^2 .

It is an emirp because it is prime and its reverse (965110127) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 721011569 - 2⁴ = 721011553 is a prime.

It is a super-2 number, since 2×721011569² = 1039715365263683522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (721011539) 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, 360505784 + 360505785.

It is an arithmetic number, because the mean of its divisors is an integer number (360505785).

Almost surely, 2^721011569 is an apocalyptic number.

It is an amenable number.

721011569 is a deficient number, since it is larger than the sum of its proper divisors (1).

721011569 is an equidigital number, since it uses as much as digits as its factorization.

721011569 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3780, while the sum is 32.

The square root of 721011569 is about 26851.6585893684. The cubic root of 721011569 is about 896.7004982713.

The spelling of 721011569 in words is "seven hundred twenty-one million, eleven thousand, five hundred sixty-nine".