863871078781 has 4 divisors (see below), whose sum is σ = 893659736700. Its totient is φ = 834082420864.

The previous prime is 863871078761. The next prime is 863871078799. The reversal of 863871078781 is 187870178368.

863871078781 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in 2 ways, for example, as 469067463225 + 394803615556 = 684885^2 + 628334^2 .

It is a cyclic number.

It is not a de Polignac number, because 863871078781 - 2¹⁹ = 863870554493 is a prime.

It is a super-2 number, since 2×863871078781² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (863871078731) 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, 14894328916 + ... + 14894328973.

It is an arithmetic number, because the mean of its divisors is an integer number (223414934175).

Almost surely, 2^863871078781 is an apocalyptic number.

It is an amenable number.

863871078781 is a deficient number, since it is larger than the sum of its proper divisors (29788657919).

863871078781 is a wasteful number, since it uses less digits than its factorization.

863871078781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29788657918.

The product of its (nonzero) digits is 25288704, while the sum is 64.

The spelling of 863871078781 in words is "eight hundred sixty-three billion, eight hundred seventy-one million, seventy-eight thousand, seven hundred eighty-one".