721390559 has 2 divisors, whose sum is σ = 721390560. Its totient is φ = 721390558.

The previous prime is 721390547. The next prime is 721390583. The reversal of 721390559 is 955093127.

It is a weak prime.

It is an emirp because it is prime and its reverse (955093127) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 721390559 - 2⁴ = 721390543 is a prime.

It is a super-2 number, since 2×721390559² = 1040808677228664962, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (721390589) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360695279 + 360695280.

It is an arithmetic number, because the mean of its divisors is an integer number (360695280).

Almost surely, 2^721390559 is an apocalyptic number.

721390559 is a deficient number, since it is larger than the sum of its proper divisors (1).

721390559 is an equidigital number, since it uses as much as digits as its factorization.

721390559 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 85050, while the sum is 41.

The square root of 721390559 is about 26858.7147682088. The cubic root of 721390559 is about 896.8575835894.

The spelling of 721390559 in words is "seven hundred twenty-one million, three hundred ninety thousand, five hundred fifty-nine".