646125121 has 8 divisors (see below), whose sum is σ = 668229120. Its totient is φ = 624369408.

The previous prime is 646125113. The next prime is 646125163. The reversal of 646125121 is 121521646.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 646125121 - 2³ = 646125113 is a prime.

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 646125121.

It is not an unprimeable number, because it can be changed into a prime (646125101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 83296 + ... + 90721.

It is an arithmetic number, because the mean of its divisors is an integer number (83528640).

Almost surely, 2^646125121 is an apocalyptic number.

It is an amenable number.

646125121 is a deficient number, since it is larger than the sum of its proper divisors (22103999).

646125121 is a wasteful number, since it uses less digits than its factorization.

646125121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 174143.

The product of its digits is 2880, while the sum is 28.

The square root of 646125121 is about 25418.9913450554. The cubic root of 646125121 is about 864.5143546750.

Adding to 646125121 its reverse (121521646), we get a palindrome (767646767).

The spelling of 646125121 in words is "six hundred forty-six million, one hundred twenty-five thousand, one hundred twenty-one".