640003121 has 8 divisors (see below), whose sum is σ = 648735360. Its totient is φ = 631330128.

The previous prime is 640003093. The next prime is 640003141. The reversal of 640003121 is 121300046.

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 640003121 - 2⁶ = 640003057 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 640003121.

It is not an unprimeable number, because it can be changed into a prime (640003141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7160 + ... + 36486.

It is an arithmetic number, because the mean of its divisors is an integer number (81091920).

Almost surely, 2^640003121 is an apocalyptic number.

It is an amenable number.

640003121 is a deficient number, since it is larger than the sum of its proper divisors (8732239).

640003121 is a wasteful number, since it uses less digits than its factorization.

640003121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29623.

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 640003121 is about 25298.2829654504. The cubic root of 640003121 is about 861.7752768419.

Adding to 640003121 its reverse (121300046), we get a palindrome (761303167).

The spelling of 640003121 in words is "six hundred forty million, three thousand, one hundred twenty-one".