861589380 has 24 divisors (see below), whose sum is σ = 2412450432. Its totient is φ = 229757152.

The previous prime is 861589373. The next prime is 861589403. The reversal of 861589380 is 83985168.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7179852 + ... + 7179971.

It is an arithmetic number, because the mean of its divisors is an integer number (100518768).

Almost surely, 2^861589380 is an apocalyptic number.

It is an amenable number.

861589380 is an abundant number, since it is smaller than the sum of its proper divisors (1550861052).

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

861589380 is a wasteful number, since it uses less digits than its factorization.

861589380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14359835 (or 14359833 counting only the distinct ones).

The product of its (nonzero) digits is 414720, while the sum is 48.

The square root of 861589380 is about 29352.8427924792. The cubic root of 861589380 is about 951.5540142605.

It can be divided in two parts, 861 and 589380, that added together give a triangular number (590241 = T₁₀₈₆).

The spelling of 861589380 in words is "eight hundred sixty-one million, five hundred eighty-nine thousand, three hundred eighty".