721708423 has 2 divisors, whose sum is σ = 721708424. Its totient is φ = 721708422.

The previous prime is 721708399. The next prime is 721708447. The reversal of 721708423 is 324807127.

It is a balanced prime because it is at equal distance from previous prime (721708399) and next prime (721708447).

It is a cyclic number.

It is not a de Polignac number, because 721708423 - 2⁵ = 721708391 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (721709423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360854211 + 360854212.

It is an arithmetic number, because the mean of its divisors is an integer number (360854212).

Almost surely, 2^721708423 is an apocalyptic number.

721708423 is a deficient number, since it is larger than the sum of its proper divisors (1).

721708423 is an equidigital number, since it uses as much as digits as its factorization.

721708423 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18816, while the sum is 34.

The square root of 721708423 is about 26864.6314510361. The cubic root of 721708423 is about 896.9892907368.

The spelling of 721708423 in words is "seven hundred twenty-one million, seven hundred eight thousand, four hundred twenty-three".