863955840 has 256 divisors, whose sum is σ = 3163795200. Its totient is φ = 198328320.

The previous prime is 863955811. The next prime is 863955853. The reversal of 863955840 is 48559368.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 863955840.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 400204 + ... + 402356.

It is an arithmetic number, because the mean of its divisors is an integer number (12358575).

Almost surely, 2^863955840 is an apocalyptic number.

863955840 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 863955840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1581897600).

863955840 is an abundant number, since it is smaller than the sum of its proper divisors (2299839360).

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

863955840 is a wasteful number, since it uses less digits than its factorization.

863955840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2205 (or 2193 counting only the distinct ones).

The product of its (nonzero) digits is 1036800, while the sum is 48.

The square root of 863955840 is about 29393.1257269451. The cubic root of 863955840 is about 952.4244041381.

It can be divided in two parts, 86395 and 5840, that added together give a triangular number (92235 = T₄₂₉).

The spelling of 863955840 in words is "eight hundred sixty-three million, nine hundred fifty-five thousand, eight hundred forty".