861939 has 24 divisors (see below), whose sum is σ = 1375920. Its totient is φ = 516672.

The previous prime is 861937. The next prime is 861941. The reversal of 861939 is 939168.

861939 is a `hidden beast` number, since 8 + 619 + 39 = 666.

It is an interprime number because it is at equal distance from previous prime (861937) and next prime (861941).

It is not a de Polignac number, because 861939 - 2¹ = 861937 is a prime.

It is not an unprimeable number, because it can be changed into a prime (861937) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6132 + ... + 6270.

It is an arithmetic number, because the mean of its divisors is an integer number (57330).

2⁸⁶¹⁹³⁹ is an apocalyptic number.

861939 is a deficient number, since it is larger than the sum of its proper divisors (513981).

861939 is a wasteful number, since it uses less digits than its factorization.

861939 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 211 (or 208 counting only the distinct ones).

The product of its digits is 11664, while the sum is 36.

The square root of 861939 is about 928.4066996742. The cubic root of 861939 is about 95.1682705620.

It can be divided in two parts, 86 and 1939, that added together give a square (2025 = 45²).

The spelling of 861939 in words is "eight hundred sixty-one thousand, nine hundred thirty-nine".