640412501 has 2 divisors, whose sum is σ = 640412502. Its totient is φ = 640412500.

The previous prime is 640412489. The next prime is 640412503. The reversal of 640412501 is 105214046.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 633730276 + 6682225 = 25174^2 + 2585^2 .

It is a cyclic number.

It is not a de Polignac number, because 640412501 - 2¹⁰ = 640411477 is a prime.

It is a Sophie Germain prime.

Together with 640412503, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (640412503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320206250 + 320206251.

It is an arithmetic number, because the mean of its divisors is an integer number (320206251).

Almost surely, 2^640412501 is an apocalyptic number.

It is an amenable number.

640412501 is a deficient number, since it is larger than the sum of its proper divisors (1).

640412501 is an equidigital number, since it uses as much as digits as its factorization.

640412501 is an odious number, because the sum of its binary digits is odd.

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

The square root of 640412501 is about 25306.3727349456. The cubic root of 640412501 is about 861.9589834292.

Adding to 640412501 its reverse (105214046), we get a palindrome (745626547).

The spelling of 640412501 in words is "six hundred forty million, four hundred twelve thousand, five hundred one".