64878569761 has 2 divisors, whose sum is σ = 64878569762. Its totient is φ = 64878569760.

The previous prime is 64878569737. The next prime is 64878569831. The reversal of 64878569761 is 16796587846.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 62372065536 + 2506504225 = 249744^2 + 50065^2 .

It is a cyclic number.

It is not a de Polignac number, because 64878569761 - 2⁵ = 64878569729 is a prime.

It is not a weakly prime, because it can be changed into another prime (64878564761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32439284880 + 32439284881.

It is an arithmetic number, because the mean of its divisors is an integer number (32439284881).

Almost surely, 2^64878569761 is an apocalyptic number.

It is an amenable number.

64878569761 is a deficient number, since it is larger than the sum of its proper divisors (1).

64878569761 is an equidigital number, since it uses as much as digits as its factorization.

64878569761 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 121927680, while the sum is 67.

The spelling of 64878569761 in words is "sixty-four billion, eight hundred seventy-eight million, five hundred sixty-nine thousand, seven hundred sixty-one".