640310121 has 24 divisors (see below), whose sum is σ = 1010284704. Its totient is φ = 387562560.

The previous prime is 640310113. The next prime is 640310137. The reversal of 640310121 is 121013046.

It is a happy number.

640310121 is a `hidden beast` number, since 640 + 3 + 1 + 0 + 1 + 21 = 666.

640310121 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 640310121 - 2³ = 640310113 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 640310094 and 640310103.

It is not an unprimeable number, because it can be changed into a prime (640350121) 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, 81070 + ... + 88616.

It is an arithmetic number, because the mean of its divisors is an integer number (42095196).

Almost surely, 2^640310121 is an apocalyptic number.

It is an amenable number.

640310121 is a deficient number, since it is larger than the sum of its proper divisors (369974583).

640310121 is a wasteful number, since it uses less digits than its factorization.

640310121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8421 (or 8418 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 640310121 is about 25304.3498434558. The cubic root of 640310121 is about 861.9130484193.

Adding to 640310121 its reverse (121013046), we get a palindrome (761323167).

The spelling of 640310121 in words is "six hundred forty million, three hundred ten thousand, one hundred twenty-one".