641642501 has 2 divisors, whose sum is σ = 641642502. Its totient is φ = 641642500.

The previous prime is 641642489. The next prime is 641642621. The reversal of 641642501 is 105246146.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 603881476 + 37761025 = 24574^2 + 6145^2 .

It is a cyclic number.

It is not a de Polignac number, because 641642501 - 2¹⁰ = 641641477 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (641602501) 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 as a sum of consecutive naturals, namely, 320821250 + 320821251.

It is an arithmetic number, because the mean of its divisors is an integer number (320821251).

Almost surely, 2^641642501 is an apocalyptic number.

It is an amenable number.

641642501 is a deficient number, since it is larger than the sum of its proper divisors (1).

641642501 is an equidigital number, since it uses as much as digits as its factorization.

641642501 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5760, while the sum is 29.

The square root of 641642501 is about 25330.6632562197. The cubic root of 641642501 is about 862.5104673098.

Adding to 641642501 its reverse (105246146), we get a palindrome (746888647).

The spelling of 641642501 in words is "six hundred forty-one million, six hundred forty-two thousand, five hundred one".