64642446040729 has 2 divisors, whose sum is σ = 64642446040730. Its totient is φ = 64642446040728.

The previous prime is 64642446040643. The next prime is 64642446040751. The reversal of 64642446040729 is 92704064424646.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 45485892728329 + 19156553312400 = 6744323^2 + 4376820^2 .

It is a cyclic number.

It is not a de Polignac number, because 64642446040729 - 2²¹ = 64642443943577 is a prime.

It is not a weakly prime, because it can be changed into another prime (64642446040829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32321223020364 + 32321223020365.

It is an arithmetic number, because the mean of its divisors is an integer number (32321223020365).

Almost surely, 2^{64642446040729} is an apocalyptic number.

It is an amenable number.

64642446040729 is a deficient number, since it is larger than the sum of its proper divisors (1).

64642446040729 is an equidigital number, since it uses as much as digits as its factorization.

64642446040729 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 55738368, while the sum is 58.

The spelling of 64642446040729 in words is "sixty-four trillion, six hundred forty-two billion, four hundred forty-six million, forty thousand, seven hundred twenty-nine".