1723521689 has 2 divisors, whose sum is σ = 1723521690. Its totient is φ = 1723521688.

The previous prime is 1723521661. The next prime is 1723521691. The reversal of 1723521689 is 9861253271.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1622720089 + 100801600 = 40283^2 + 10040^2 .

It is a cyclic number.

It is not a de Polignac number, because 1723521689 - 2²⁰ = 1722473113 is a prime.

Together with 1723521691, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1723524689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 861760844 + 861760845.

It is an arithmetic number, because the mean of its divisors is an integer number (861760845).

Almost surely, 2^1723521689 is an apocalyptic number.

It is an amenable number.

1723521689 is a deficient number, since it is larger than the sum of its proper divisors (1).

1723521689 is an equidigital number, since it uses as much as digits as its factorization.

1723521689 is an evil number, because the sum of its binary digits is even.

The product of its digits is 181440, while the sum is 44.

The square root of 1723521689 is about 41515.3187269470. The cubic root of 1723521689 is about 1198.9624571144.

The spelling of 1723521689 in words is "one billion, seven hundred twenty-three million, five hundred twenty-one thousand, six hundred eighty-nine".