861381884 has 12 divisors (see below), whose sum is σ = 1644456408. Its totient is φ = 391537200.

The previous prime is 861381863. The next prime is 861381889. The reversal of 861381884 is 488183168.

It is a happy number.

It is a hoax number, since the sum of its digits (47) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861381889) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9788387 + ... + 9788474.

It is an arithmetic number, because the mean of its divisors is an integer number (137038034).

Almost surely, 2^861381884 is an apocalyptic number.

It is an amenable number.

861381884 is a deficient number, since it is larger than the sum of its proper divisors (783074524).

861381884 is a wasteful number, since it uses less digits than its factorization.

861381884 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19576876 (or 19576874 counting only the distinct ones).

The product of its digits is 294912, while the sum is 47.

The square root of 861381884 is about 29349.3080668012. The cubic root of 861381884 is about 951.4776207531.

The spelling of 861381884 in words is "eight hundred sixty-one million, three hundred eighty-one thousand, eight hundred eighty-four".