678615638543 has 4 divisors (see below), whose sum is σ = 678638030760. Its totient is φ = 678593246328.

The previous prime is 678615638509. The next prime is 678615638551. The reversal of 678615638543 is 345836516876.

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

It is a cyclic number.

It is not a de Polignac number, because 678615638543 - 2⁶ = 678615638479 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (678615638443) 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, 11150588 + ... + 11211281.

It is an arithmetic number, because the mean of its divisors is an integer number (169659507690).

Almost surely, 2^678615638543 is an apocalyptic number.

678615638543 is a deficient number, since it is larger than the sum of its proper divisors (22392217).

678615638543 is a wasteful number, since it uses less digits than its factorization.

678615638543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22392216.

The product of its digits is 87091200, while the sum is 62.

The spelling of 678615638543 in words is "six hundred seventy-eight billion, six hundred fifteen million, six hundred thirty-eight thousand, five hundred forty-three".