561145 has 16 divisors (see below), whose sum is σ = 740880. Its totient is φ = 405504.

The previous prime is 561109. The next prime is 561161. The reversal of 561145 is 541165.

561145 = T₂₀ + T₂₁ + ... + T₁₄₉.

561145 = 59² + 60² + ... + 123².

It can be written as a sum of positive squares in 8 ways, for example, as 109561 + 451584 = 331^2 + 672^2 .

It is a cyclic number.

It is not a de Polignac number, because 561145 - 2¹⁹ = 36857 is a prime.

It is a super-2 number, since 2×561145² = 629767422050, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5737 + ... + 5833.

It is an arithmetic number, because the mean of its divisors is an integer number (46305).

2⁵⁶¹¹⁴⁵ is an apocalyptic number.

It is an amenable number.

561145 is a deficient number, since it is larger than the sum of its proper divisors (179735).

561145 is a wasteful number, since it uses less digits than its factorization.

561145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 204.

The product of its digits is 600, while the sum is 22.

The square root of 561145 is about 749.0961220030. The cubic root of 561145 is about 82.4818447959.

The spelling of 561145 in words is "five hundred sixty-one thousand, one hundred forty-five".