646245101 has 2 divisors, whose sum is σ = 646245102. Its totient is φ = 646245100.

The previous prime is 646245073. The next prime is 646245143. The reversal of 646245101 is 101542646.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 545222500 + 101022601 = 23350^2 + 10051^2 .

It is a cyclic number.

It is not a de Polignac number, because 646245101 - 2¹⁰ = 646244077 is a prime.

It is a Sophie Germain 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 (646245181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323122550 + 323122551.

It is an arithmetic number, because the mean of its divisors is an integer number (323122551).

Almost surely, 2^646245101 is an apocalyptic number.

It is an amenable number.

646245101 is a deficient number, since it is larger than the sum of its proper divisors (1).

646245101 is an equidigital number, since it uses as much as digits as its factorization.

646245101 is an evil number, because the sum of its binary digits is even.

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

The square root of 646245101 is about 25421.3512819441. The cubic root of 646245101 is about 864.5678623778.

Adding to 646245101 its reverse (101542646), we get a palindrome (747787747).

The spelling of 646245101 in words is "six hundred forty-six million, two hundred forty-five thousand, one hundred one".