861247156 has 48 divisors (see below), whose sum is σ = 1885226112. Its totient is φ = 334454400.

The previous prime is 861247141. The next prime is 861247157. The reversal of 861247156 is 651742168.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861247157) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 93226 + ... + 102046.

It is an arithmetic number, because the mean of its divisors is an integer number (39275544).

Almost surely, 2^861247156 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 861247156, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (942613056).

861247156 is an abundant number, since it is smaller than the sum of its proper divisors (1023978956).

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

861247156 is a wasteful number, since it uses less digits than its factorization.

861247156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9160 (or 9158 counting only the distinct ones).

The product of its digits is 80640, while the sum is 40.

The square root of 861247156 is about 29347.0127270221. The cubic root of 861247156 is about 951.4280115677.

The spelling of 861247156 in words is "eight hundred sixty-one million, two hundred forty-seven thousand, one hundred fifty-six".