1723561 has 4 divisors (see below), whose sum is σ = 1969792. Its totient is φ = 1477332.

The previous prime is 1723541. The next prime is 1723573. The reversal of 1723561 is 1653271.

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: 1653271 = 37 ⋅44683.

It is a cyclic number.

It is not a de Polignac number, because 1723561 - 2¹¹ = 1721513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1723541) 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, 123105 + ... + 123118.

It is an arithmetic number, because the mean of its divisors is an integer number (492448).

2^1723561 is an apocalyptic number.

It is an amenable number.

1723561 is a deficient number, since it is larger than the sum of its proper divisors (246231).

1723561 is an equidigital number, since it uses as much as digits as its factorization.

1723561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 246230.

The product of its digits is 1260, while the sum is 25.

The square root of 1723561 is about 1312.8446214233. The cubic root of 1723561 is about 119.8971572570.

The spelling of 1723561 in words is "one million, seven hundred twenty-three thousand, five hundred sixty-one".