678132967781 has 4 divisors (see below), whose sum is σ = 679465253100. Its totient is φ = 676800682464.

The previous prime is 678132967769. The next prime is 678132967783. The reversal of 678132967781 is 187769231876.

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 444834307681 + 233298660100 = 666959^2 + 483010^2 .

It is a cyclic number.

It is not a de Polignac number, because 678132967781 - 2¹⁰ = 678132966757 is a prime.

It is a super-2 number, since 2×678132967781² (a number of 24 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 (678132967783) 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, 666141896 + ... + 666142913.

It is an arithmetic number, because the mean of its divisors is an integer number (169866313275).

Almost surely, 2^678132967781 is an apocalyptic number.

It is an amenable number.

678132967781 is a deficient number, since it is larger than the sum of its proper divisors (1332285319).

678132967781 is a wasteful number, since it uses less digits than its factorization.

678132967781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1332285318.

The product of its digits is 42674688, while the sum is 65.

The spelling of 678132967781 in words is "six hundred seventy-eight billion, one hundred thirty-two million, nine hundred sixty-seven thousand, seven hundred eighty-one".