877561 has 4 divisors (see below), whose sum is σ = 880000. Its totient is φ = 875124.

The previous prime is 877543. The next prime is 877567. The reversal of 877561 is 165778.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 165778 = 2 ⋅82889.

It is a cyclic number.

It is not a de Polignac number, because 877561 - 2¹¹ = 875513 is a prime.

It is a super-2 number, since 2×877561² = 1540226617442, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (877567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 561 + ... + 1438.

It is an arithmetic number, because the mean of its divisors is an integer number (220000).

2⁸⁷⁷⁵⁶¹ is an apocalyptic number.

It is an amenable number.

877561 is a deficient number, since it is larger than the sum of its proper divisors (2439).

877561 is a wasteful number, since it uses less digits than its factorization.

877561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2438.

The product of its digits is 11760, while the sum is 34.

The square root of 877561 is about 936.7822585852. The cubic root of 877561 is about 95.7397828518.

It can be divided in two parts, 8775 and 61, that added together give a square (8836 = 94²).

The spelling of 877561 in words is "eight hundred seventy-seven thousand, five hundred sixty-one".