561749 has 4 divisors (see below), whose sum is σ = 571020. Its totient is φ = 552480.

The previous prime is 561733. The next prime is 561761. The reversal of 561749 is 947165.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 947165 = 5 ⋅189433.

It can be written as a sum of positive squares in 2 ways, for example, as 46225 + 515524 = 215^2 + 718^2 .

It is a cyclic number.

It is not a de Polignac number, because 561749 - 2⁴ = 561733 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521749) 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, 4544 + ... + 4665.

It is an arithmetic number, because the mean of its divisors is an integer number (142755).

561749 is a Friedman number, since it can be written as 61*(9*4^5-7), using all its digits and the basic arithmetic operations.

2⁵⁶¹⁷⁴⁹ is an apocalyptic number.

It is an amenable number.

561749 is a deficient number, since it is larger than the sum of its proper divisors (9271).

561749 is an equidigital number, since it uses as much as digits as its factorization.

561749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9270.

The product of its digits is 7560, while the sum is 32.

The square root of 561749 is about 749.4991661103. The cubic root of 561749 is about 82.5114278629.

The spelling of 561749 in words is "five hundred sixty-one thousand, seven hundred forty-nine".