678440101 has 2 divisors, whose sum is σ = 678440102. Its totient is φ = 678440100.

The previous prime is 678440069. The next prime is 678440143. The reversal of 678440101 is 101044876.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 569967876 + 108472225 = 23874^2 + 10415^2 .

It is a cyclic number.

It is not a de Polignac number, because 678440101 - 2⁵ = 678440069 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (678440401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 339220050 + 339220051.

It is an arithmetic number, because the mean of its divisors is an integer number (339220051).

Almost surely, 2^678440101 is an apocalyptic number.

It is an amenable number.

678440101 is a deficient number, since it is larger than the sum of its proper divisors (1).

678440101 is an equidigital number, since it uses as much as digits as its factorization.

678440101 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5376, while the sum is 31.

The square root of 678440101 is about 26046.8827501488. The cubic root of 678440101 is about 878.6930068451.

Adding to 678440101 its reverse (101044876), we get a palindrome (779484977).

The spelling of 678440101 in words is "six hundred seventy-eight million, four hundred forty thousand, one hundred one".