721544533 has 2 divisors, whose sum is σ = 721544534. Its totient is φ = 721544532.

The previous prime is 721544521. The next prime is 721544543. The reversal of 721544533 is 335445127.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 659102929 + 62441604 = 25673^2 + 7902^2 .

It is an emirp because it is prime and its reverse (335445127) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 721544533 - 2⁵ = 721544501 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (721544503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360772266 + 360772267.

It is an arithmetic number, because the mean of its divisors is an integer number (360772267).

Almost surely, 2^721544533 is an apocalyptic number.

It is an amenable number.

721544533 is a deficient number, since it is larger than the sum of its proper divisors (1).

721544533 is an equidigital number, since it uses as much as digits as its factorization.

721544533 is an evil number, because the sum of its binary digits is even.

The product of its digits is 50400, while the sum is 34.

The square root of 721544533 is about 26861.5809847447. The cubic root of 721544533 is about 896.9213876431.

The spelling of 721544533 in words is "seven hundred twenty-one million, five hundred forty-four thousand, five hundred thirty-three".