561538 has 4 divisors (see below), whose sum is σ = 842310. Its totient is φ = 280768.

The previous prime is 561529. The next prime is 561551. The reversal of 561538 is 835165.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 835165 = 5 ⋅167033.

It can be written as a sum of positive squares in only one way, i.e., 522729 + 38809 = 723^2 + 197^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 140383 + ... + 140386.

2⁵⁶¹⁵³⁸ is an apocalyptic number.

561538 is a deficient number, since it is larger than the sum of its proper divisors (280772).

561538 is a wasteful number, since it uses less digits than its factorization.

561538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 280771.

The product of its digits is 3600, while the sum is 28.

The square root of 561538 is about 749.3583922263. The cubic root of 561538 is about 82.5010957920.

The spelling of 561538 in words is "five hundred sixty-one thousand, five hundred thirty-eight".