861780036 has 192 divisors, whose sum is σ = 2402426880. Its totient is φ = 238049280.

The previous prime is 861780011. The next prime is 861780043. The reversal of 861780036 is 630087168.

861780036 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×861780036² = 1485329660896322592, which contains 22 as substring.

It is a hoax number, since the sum of its digits (39) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a junction number, because it is equal to n+sod(n) for n = 861779976 and 861780003.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 7626316 + ... + 7626428.

It is an arithmetic number, because the mean of its divisors is an integer number (12512640).

Almost surely, 2^861780036 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 861780036, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1201213440).

861780036 is an abundant number, since it is smaller than the sum of its proper divisors (1540646844).

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

861780036 is a wasteful number, since it uses less digits than its factorization.

861780036 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 266 (or 264 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 39.

The square root of 861780036 is about 29356.0902710153. The cubic root of 861780036 is about 951.6241969973.

The spelling of 861780036 in words is "eight hundred sixty-one million, seven hundred eighty thousand, thirty-six".