646219001 has 2 divisors, whose sum is σ = 646219002. Its totient is φ = 646219000.

The previous prime is 646218997. The next prime is 646219003. The reversal of 646219001 is 100912646.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 339443776 + 306775225 = 18424^2 + 17515^2 .

It is a cyclic number.

It is not a de Polignac number, because 646219001 - 2² = 646218997 is a prime.

Together with 646219003, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (646219003) 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, 323109500 + 323109501.

It is an arithmetic number, because the mean of its divisors is an integer number (323109501).

Almost surely, 2^646219001 is an apocalyptic number.

It is an amenable number.

646219001 is a deficient number, since it is larger than the sum of its proper divisors (1).

646219001 is an equidigital number, since it uses as much as digits as its factorization.

646219001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2592, while the sum is 29.

The square root of 646219001 is about 25420.8379287544. The cubic root of 646219001 is about 864.5562230761.

The spelling of 646219001 in words is "six hundred forty-six million, two hundred nineteen thousand, one".