861930 has 48 divisors (see below), whose sum is σ = 2292264. Its totient is φ = 224640.

The previous prime is 861929. The next prime is 861937. The reversal of 861930 is 39168.

It can be written as a sum of positive squares in 4 ways, for example, as 356409 + 505521 = 597^2 + 711^2 .

861930 is an undulating number in base 13.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 861894 and 861903.

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

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5412 + ... + 5568.

2⁸⁶¹⁹³⁰ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 861930, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1146132).

861930 is an abundant number, since it is smaller than the sum of its proper divisors (1430334).

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

861930 is a wasteful number, since it uses less digits than its factorization.

861930 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 231 (or 228 counting only the distinct ones).

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

The square root of 861930 is about 928.4018526479. The cubic root of 861930 is about 95.1679393253.

It can be divided in two parts, 8619 and 30, that added together give a square (8649 = 93²).

The spelling of 861930 in words is "eight hundred sixty-one thousand, nine hundred thirty".