861993 has 12 divisors (see below), whose sum is σ = 1358448. Its totient is φ = 522360.

The previous prime is 861979. The next prime is 861997. The reversal of 861993 is 399168.

861993 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 861993 - 2⁴ = 861977 is a prime.

It is not an unprimeable number, because it can be changed into a prime (861997) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4255 + ... + 4452.

It is an arithmetic number, because the mean of its divisors is an integer number (113204).

2⁸⁶¹⁹⁹³ is an apocalyptic number.

It is an amenable number.

861993 is a deficient number, since it is larger than the sum of its proper divisors (496455).

861993 is a wasteful number, since it uses less digits than its factorization.

861993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8724 (or 8721 counting only the distinct ones).

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

The square root of 861993 is about 928.4357813010. The cubic root of 861993 is about 95.1702579336.

It can be divided in two parts, 8 and 61993, that added together give a square (62001 = 249²).

The spelling of 861993 in words is "eight hundred sixty-one thousand, nine hundred ninety-three".