678751221245 has 6 divisors (see below), whose sum is σ = 814503676158. Its totient is φ = 542999503224.

The previous prime is 678751221223. The next prime is 678751221251. The reversal of 678751221245 is 542122157876.

It can be written as a sum of positive squares in only one way, i.e., 543000976996 + 135750244249 = 736886^2 + 368443^2 .

It is not a de Polignac number, because 678751221245 - 2¹⁰ = 678751220221 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 678751221193 and 678751221202.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1657994 + ... + 2026436.

It is an arithmetic number, because the mean of its divisors is an integer number (135750612693).

Almost surely, 2^678751221245 is an apocalyptic number.

It is an amenable number.

678751221245 is a deficient number, since it is larger than the sum of its proper divisors (135752454913).

678751221245 is an frugal number, since it uses more digits than its factorization.

678751221245 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 736891 (or 368448 counting only the distinct ones).

The product of its digits is 1881600, while the sum is 50.

The spelling of 678751221245 in words is "six hundred seventy-eight billion, seven hundred fifty-one million, two hundred twenty-one thousand, two hundred forty-five".