815860 has 36 divisors (see below), whose sum is σ = 1824228. Its totient is φ = 306432.

The previous prime is 815851. The next prime is 815869. The reversal of 815860 is 68518.

815860 = T₇₃₆ + T₇₃₇ + T₇₃₈.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (815851) and next prime (815869).

It can be written as a sum of positive squares in 2 ways, for example, as 116964 + 698896 = 342^2 + 836^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (815869) by changing a digit.

815860 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 11 ways as a sum of consecutive naturals, for example, 7164 + ... + 7276.

It is an arithmetic number, because the mean of its divisors is an integer number (50673).

2⁸¹⁵⁸⁶⁰ is an apocalyptic number.

815860 is the 452-nd decagonal number.

815860 is the 738-th centered triangular number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 815860, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (912114).

815860 is an abundant number, since it is smaller than the sum of its proper divisors (1008368).

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

815860 is a wasteful number, since it uses less digits than its factorization.

815860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160 (or 139 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 28.

The square root of 815860 is about 903.2496886244. The cubic root of 815860 is about 93.4412300946.

The spelling of 815860 in words is "eight hundred fifteen thousand, eight hundred sixty".