678418221 has 16 divisors (see below), whose sum is σ = 979912640. Its totient is φ = 417484080.

The previous prime is 678418211. The next prime is 678418283. The reversal of 678418221 is 122814876.

It is a happy number.

It is not a de Polignac number, because 678418221 - 2⁶ = 678418157 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 678418221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (678418211) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 44875 + ... + 58056.

It is an arithmetic number, because the mean of its divisors is an integer number (61244540).

Almost surely, 2^678418221 is an apocalyptic number.

It is an amenable number.

678418221 is a deficient number, since it is larger than the sum of its proper divisors (301494419).

678418221 is a wasteful number, since it uses less digits than its factorization.

678418221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102973 (or 102947 counting only the distinct ones).

The product of its digits is 43008, while the sum is 39.

The square root of 678418221 is about 26046.4627348897. The cubic root of 678418221 is about 878.6835606613.

The spelling of 678418221 in words is "six hundred seventy-eight million, four hundred eighteen thousand, two hundred twenty-one".