721818863 has 2 divisors, whose sum is σ = 721818864. Its totient is φ = 721818862.

The previous prime is 721818841. The next prime is 721818907. The reversal of 721818863 is 368818127.

721818863 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an a-pointer prime, because the next prime (721818907) can be obtained adding 721818863 to its sum of digits (44).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 721818863 - 2¹⁶ = 721753327 is a prime.

It is a super-2 number, since 2×721818863² = 1042044941965225538, 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 (721818833) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360909431 + 360909432.

It is an arithmetic number, because the mean of its divisors is an integer number (360909432).

Almost surely, 2^721818863 is an apocalyptic number.

721818863 is a deficient number, since it is larger than the sum of its proper divisors (1).

721818863 is an equidigital number, since it uses as much as digits as its factorization.

721818863 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 129024, while the sum is 44.

The square root of 721818863 is about 26866.6868631024. The cubic root of 721818863 is about 897.0350425674.

The spelling of 721818863 in words is "seven hundred twenty-one million, eight hundred eighteen thousand, eight hundred sixty-three".