1561523 has 4 divisors (see below), whose sum is σ = 1565520. Its totient is φ = 1557528.

The previous prime is 1561519. The next prime is 1561529. The reversal of 1561523 is 3251651.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1561523 - 2² = 1561519 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1561529) 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, 1340 + ... + 2217.

It is an arithmetic number, because the mean of its divisors is an integer number (391380).

2^1561523 is an apocalyptic number.

1561523 is a deficient number, since it is larger than the sum of its proper divisors (3997).

1561523 is an equidigital number, since it uses as much as digits as its factorization.

1561523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3996.

The product of its digits is 900, while the sum is 23.

The square root of 1561523 is about 1249.6091388910. The cubic root of 1561523 is about 116.0155300254.

The spelling of 1561523 in words is "one million, five hundred sixty-one thousand, five hundred twenty-three".