644342121243467 has 2 divisors, whose sum is σ = 644342121243468. Its totient is φ = 644342121243466.

The previous prime is 644342121243413. The next prime is 644342121243497. The reversal of 644342121243467 is 764342121243446.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 644342121243467 - 2³⁰ = 644341047501643 is a prime.

It is not a weakly prime, because it can be changed into another prime (644342121243497) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322171060621733 + 322171060621734.

It is an arithmetic number, because the mean of its divisors is an integer number (322171060621734).

Almost surely, 2^{644342121243467} is an apocalyptic number.

644342121243467 is a deficient number, since it is larger than the sum of its proper divisors (1).

644342121243467 is an equidigital number, since it uses as much as digits as its factorization.

644342121243467 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18579456, while the sum is 53.

The spelling of 644342121243467 in words is "six hundred forty-four trillion, three hundred forty-two billion, one hundred twenty-one million, two hundred forty-three thousand, four hundred sixty-seven".