641550461 has 2 divisors, whose sum is σ = 641550462. Its totient is φ = 641550460.

The previous prime is 641550451. The next prime is 641550463. The reversal of 641550461 is 164055146.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 526932025 + 114618436 = 22955^2 + 10706^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-641550461 is a prime.

Together with 641550463, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (641550463) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320775230 + 320775231.

It is an arithmetic number, because the mean of its divisors is an integer number (320775231).

Almost surely, 2^641550461 is an apocalyptic number.

It is an amenable number.

641550461 is a deficient number, since it is larger than the sum of its proper divisors (1).

641550461 is an equidigital number, since it uses as much as digits as its factorization.

641550461 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14400, while the sum is 32.

The square root of 641550461 is about 25328.8464206327. The cubic root of 641550461 is about 862.4692245828.

The spelling of 641550461 in words is "six hundred forty-one million, five hundred fifty thousand, four hundred sixty-one".