1561573 has 4 divisors (see below), whose sum is σ = 1681708. Its totient is φ = 1441440.

The previous prime is 1561559. The next prime is 1561577. The reversal of 1561573 is 3751651.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3751651 = 31 ⋅121021.

It can be written as a sum of positive squares in 2 ways, for example, as 702244 + 859329 = 838^2 + 927^2 .

It is not a de Polignac number, because 1561573 - 2⁵ = 1561541 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561577) 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, 60048 + ... + 60073.

It is an arithmetic number, because the mean of its divisors is an integer number (420427).

2^1561573 is an apocalyptic number.

1561573 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

1561573 is a deficient number, since it is larger than the sum of its proper divisors (120135).

1561573 is a wasteful number, since it uses less digits than its factorization.

1561573 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120134.

The product of its digits is 3150, while the sum is 28.

The square root of 1561573 is about 1249.6291449866. The cubic root of 1561573 is about 116.0167682854.

It can be divided in two parts, 1561 and 573, that multiplied together give a triangular number (894453 = T₁₃₃₇).

The spelling of 1561573 in words is "one million, five hundred sixty-one thousand, five hundred seventy-three".