678722121 has 48 divisors (see below), whose sum is σ = 1234516608. Its totient is φ = 349056000.

The previous prime is 678722087. The next prime is 678722141. The reversal of 678722121 is 121227876.

It is not a de Polignac number, because 678722121 - 2⁹ = 678721609 is a prime.

It is not an unprimeable number, because it can be changed into a prime (678722141) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 65145 + ... + 74841.

It is an arithmetic number, because the mean of its divisors is an integer number (25719096).

Almost surely, 2^678722121 is an apocalyptic number.

It is an amenable number.

678722121 is a deficient number, since it is larger than the sum of its proper divisors (555794487).

678722121 is a wasteful number, since it uses less digits than its factorization.

678722121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9822 (or 9819 counting only the distinct ones).

The product of its digits is 18816, while the sum is 36.

The square root of 678722121 is about 26052.2958873110. The cubic root of 678722121 is about 878.8147442798.

Adding to 678722121 its reverse (121227876), we get a palindrome (799949997).

The spelling of 678722121 in words is "six hundred seventy-eight million, seven hundred twenty-two thousand, one hundred twenty-one".