861535 has 4 divisors (see below), whose sum is σ = 1033848. Its totient is φ = 689224.

The previous prime is 861499. The next prime is 861541. The reversal of 861535 is 535168.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-861535 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 86149 + ... + 86158.

It is an arithmetic number, because the mean of its divisors is an integer number (258462).

2⁸⁶¹⁵³⁵ is an apocalyptic number.

861535 is a deficient number, since it is larger than the sum of its proper divisors (172313).

861535 is a wasteful number, since it uses less digits than its factorization.

861535 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172312.

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

The square root of 861535 is about 928.1890971133. The cubic root of 861535 is about 95.1533994439.

The spelling of 861535 in words is "eight hundred sixty-one thousand, five hundred thirty-five".