709521 has 4 divisors (see below), whose sum is σ = 946032. Its totient is φ = 473012.

The previous prime is 709519. The next prime is 709531. The reversal of 709521 is 125907.

709521 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 125907 = 3 ⋅41969.

It is a cyclic number.

It is not a de Polignac number, because 709521 - 2¹ = 709519 is a prime.

It is a D-number.

It is a junction number, because it is equal to n+sod(n) for n = 709491 and 709500.

It is not an unprimeable number, because it can be changed into a prime (709531) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 118251 + ... + 118256.

It is an arithmetic number, because the mean of its divisors is an integer number (236508).

2⁷⁰⁹⁵²¹ is an apocalyptic number.

It is an amenable number.

709521 is a deficient number, since it is larger than the sum of its proper divisors (236511).

709521 is a wasteful number, since it uses less digits than its factorization.

709521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 236510.

The product of its (nonzero) digits is 630, while the sum is 24.

The square root of 709521 is about 842.3306951548. The cubic root of 709521 is about 89.1911474789.

It can be divided in two parts, 70 and 9521, that added together give a triangular number (9591 = T₁₃₈).

The spelling of 709521 in words is "seven hundred nine thousand, five hundred twenty-one".