644406554463367 has 2 divisors, whose sum is σ = 644406554463368. Its totient is φ = 644406554463366.

The previous prime is 644406554463271. The next prime is 644406554463383. The reversal of 644406554463367 is 763364455604446.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-644406554463367 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (644406554443367) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322203277231683 + 322203277231684.

It is an arithmetic number, because the mean of its divisors is an integer number (322203277231684).

Almost surely, 2^{644406554463367} is an apocalyptic number.

644406554463367 is a deficient number, since it is larger than the sum of its proper divisors (1).

644406554463367 is an equidigital number, since it uses as much as digits as its factorization.

644406554463367 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2090188800, while the sum is 67.

The spelling of 644406554463367 in words is "six hundred forty-four trillion, four hundred six billion, five hundred fifty-four million, four hundred sixty-three thousand, three hundred sixty-seven".