640125401 has 4 divisors (see below), whose sum is σ = 640269072. Its totient is φ = 639981732.

The previous prime is 640125389. The next prime is 640125403. The reversal of 640125401 is 104521046.

640125401 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 640125401 - 2⁶ = 640125337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (640125403) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64931 + ... + 74136.

It is an arithmetic number, because the mean of its divisors is an integer number (160067268).

Almost surely, 2^640125401 is an apocalyptic number.

It is an amenable number.

640125401 is a deficient number, since it is larger than the sum of its proper divisors (143671).

640125401 is a wasteful number, since it uses less digits than its factorization.

640125401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143670.

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 640125401 is about 25300.6996148328. The cubic root of 640125401 is about 861.8301573921.

Adding to 640125401 its reverse (104521046), we get a palindrome (744646447).

The spelling of 640125401 in words is "six hundred forty million, one hundred twenty-five thousand, four hundred one".