721436563 has 2 divisors, whose sum is σ = 721436564. Its totient is φ = 721436562.

The previous prime is 721436461. The next prime is 721436603. The reversal of 721436563 is 365634127.

It is a strong prime.

It is an emirp because it is prime and its reverse (365634127) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-721436563 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is not a weakly prime, because it can be changed into another prime (721436063) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360718281 + 360718282.

It is an arithmetic number, because the mean of its divisors is an integer number (360718282).

Almost surely, 2^721436563 is an apocalyptic number.

721436563 is a deficient number, since it is larger than the sum of its proper divisors (1).

721436563 is an equidigital number, since it uses as much as digits as its factorization.

721436563 is an evil number, because the sum of its binary digits is even.

The product of its digits is 90720, while the sum is 37.

The square root of 721436563 is about 26859.5711618782. The cubic root of 721436563 is about 896.8766477698.

The spelling of 721436563 in words is "seven hundred twenty-one million, four hundred thirty-six thousand, five hundred sixty-three".