644045546407 has 2 divisors, whose sum is σ = 644045546408. Its totient is φ = 644045546406.

The previous prime is 644045546359. The next prime is 644045546411. The reversal of 644045546407 is 704645540446.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-644045546407 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (644045546447) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322022773203 + 322022773204.

It is an arithmetic number, because the mean of its divisors is an integer number (322022773204).

Almost surely, 2^644045546407 is an apocalyptic number.

644045546407 is a deficient number, since it is larger than the sum of its proper divisors (1).

644045546407 is an equidigital number, since it uses as much as digits as its factorization.

644045546407 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6451200, while the sum is 49.

The spelling of 644045546407 in words is "six hundred forty-four billion, forty-five million, five hundred forty-six thousand, four hundred seven".