863512815872 has 108 divisors (see below), whose sum is σ = 2053970445996. Its totient is φ = 361050439680.

The previous prime is 863512815863. The next prime is 863512815877. The reversal of 863512815872 is 278518215368.

It can be written as a sum of positive squares in 2 ways, for example, as 361999568896 + 501513246976 = 601664^2 + 708176^2 .

It is a Harshad number since it is a multiple of its sum of digits (56).

It is not an unprimeable number, because it can be changed into a prime (863512815877) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 325193 + ... + 1353800.

Almost surely, 2^863512815872 is an apocalyptic number.

863512815872 is a gapful number since it is divisible by the number (82) formed by its first and last digit.

It is an amenable number.

863512815872 is an abundant number, since it is smaller than the sum of its proper divisors (1190457630124).

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

863512815872 is a wasteful number, since it uses less digits than its factorization.

863512815872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1679064 (or 1679043 counting only the distinct ones).

The product of its digits is 6451200, while the sum is 56.

The spelling of 863512815872 in words is "eight hundred sixty-three billion, five hundred twelve million, eight hundred fifteen thousand, eight hundred seventy-two".