861804478 has 4 divisors (see below), whose sum is σ = 1292706720. Its totient is φ = 430902238.

The previous prime is 861804469. The next prime is 861804479. The reversal of 861804478 is 874408168.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861804479) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 215451118 + ... + 215451121.

It is an arithmetic number, because the mean of its divisors is an integer number (323176680).

Almost surely, 2^861804478 is an apocalyptic number.

861804478 is a deficient number, since it is larger than the sum of its proper divisors (430902242).

861804478 is a wasteful number, since it uses less digits than its factorization.

861804478 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 430902241.

The product of its (nonzero) digits is 344064, while the sum is 46.

The square root of 861804478 is about 29356.5065700945. The cubic root of 861804478 is about 951.6331936390.

The spelling of 861804478 in words is "eight hundred sixty-one million, eight hundred four thousand, four hundred seventy-eight".