861390 has 48 divisors (see below), whose sum is σ = 2375568. Its totient is φ = 215808.

The previous prime is 861361. The next prime is 861391. The reversal of 861390 is 93168.

861390 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861391) by changing a digit.

861390 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1249 + ... + 1811.

It is an arithmetic number, because the mean of its divisors is an integer number (49491).

2⁸⁶¹³⁹⁰ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 861390, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1187784).

861390 is an abundant number, since it is smaller than the sum of its proper divisors (1514178).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

861390 is a wasteful number, since it uses less digits than its factorization.

861390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 593 (or 590 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 861390 is about 928.1109847427. The cubic root of 861390 is about 95.1480609040.

It can be divided in two parts, 861 and 390, that multiplied together give a triangular number (335790 = T₈₁₉).

The spelling of 861390 in words is "eight hundred sixty-one thousand, three hundred ninety".