709921 has 2 divisors, whose sum is σ = 709922. Its totient is φ = 709920.

The previous prime is 709913. The next prime is 709927. The reversal of 709921 is 129907.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 698896 + 11025 = 836^2 + 105^2 .

It is a cyclic number.

It is not a de Polignac number, because 709921 - 2³ = 709913 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 709921.

It is not a weakly prime, because it can be changed into another prime (709927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 354960 + 354961.

It is an arithmetic number, because the mean of its divisors is an integer number (354961).

2⁷⁰⁹⁹²¹ is an apocalyptic number.

It is an amenable number.

709921 is a deficient number, since it is larger than the sum of its proper divisors (1).

709921 is an equidigital number, since it uses as much as digits as its factorization.

709921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1134, while the sum is 28.

The square root of 709921 is about 842.5680981381. The cubic root of 709921 is about 89.2079051491.

The spelling of 709921 in words is "seven hundred nine thousand, nine hundred twenty-one".