678736191 has 24 divisors (see below), whose sum is σ = 1053899904. Its totient is φ = 387419760.

The previous prime is 678736127. The next prime is 678736199. The reversal of 678736191 is 191637876.

It is a happy number.

It is not a de Polignac number, because 678736191 - 2⁶ = 678736127 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 678736191.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (678736199) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 170166 + ... + 174108.

It is an arithmetic number, because the mean of its divisors is an integer number (43912496).

Almost surely, 2^678736191 is an apocalyptic number.

678736191 is a deficient number, since it is larger than the sum of its proper divisors (375163713).

678736191 is a wasteful number, since it uses less digits than its factorization.

678736191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5131 (or 5124 counting only the distinct ones).

The product of its digits is 381024, while the sum is 48.

The square root of 678736191 is about 26052.5659196940. The cubic root of 678736191 is about 878.8208168868.

The spelling of 678736191 in words is "six hundred seventy-eight million, seven hundred thirty-six thousand, one hundred ninety-one".