644410544073641 has 2 divisors, whose sum is σ = 644410544073642. Its totient is φ = 644410544073640.

The previous prime is 644410544073607. The next prime is 644410544073683. The reversal of 644410544073641 is 146370445014446.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 408249258422041 + 236161285651600 = 20205179^2 + 15367540^2 .

It is a cyclic number.

It is not a de Polignac number, because 644410544073641 - 2⁶ = 644410544073577 is a prime.

It is a super-3 number, since 3×644410544073641³ (a number of 45 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (644410544073691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322205272036820 + 322205272036821.

It is an arithmetic number, because the mean of its divisors is an integer number (322205272036821).

Almost surely, 2^{644410544073641} is an apocalyptic number.

It is an amenable number.

644410544073641 is a deficient number, since it is larger than the sum of its proper divisors (1).

644410544073641 is an equidigital number, since it uses as much as digits as its factorization.

644410544073641 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15482880, while the sum is 53.

The spelling of 644410544073641 in words is "six hundred forty-four trillion, four hundred ten billion, five hundred forty-four million, seventy-three thousand, six hundred forty-one".