861531876 has 60 divisors (see below), whose sum is σ = 2256692592. Its totient is φ = 286606512.

The previous prime is 861531871. The next prime is 861531883. The reversal of 861531876 is 678135168.

It is not an unprimeable number, because it can be changed into a prime (861531871) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 180051 + ... + 184773.

Almost surely, 2^861531876 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 861531876, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1128346296).

861531876 is an abundant number, since it is smaller than the sum of its proper divisors (1395160716).

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

861531876 is a wasteful number, since it uses less digits than its factorization.

861531876 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5302 (or 5291 counting only the distinct ones).

The product of its digits is 241920, while the sum is 45.

The square root of 861531876 is about 29351.8632457975. The cubic root of 861531876 is about 951.5328443232.

The spelling of 861531876 in words is "eight hundred sixty-one million, five hundred thirty-one thousand, eight hundred seventy-six".