64778272609 has 2 divisors, whose sum is σ = 64778272610. Its totient is φ = 64778272608.

The previous prime is 64778272567. The next prime is 64778272679. The reversal of 64778272609 is 90627287746.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 61626573009 + 3151699600 = 248247^2 + 56140^2 .

It is a cyclic number.

It is not a de Polignac number, because 64778272609 - 2¹⁷ = 64778141537 is a prime.

It is not a weakly prime, because it can be changed into another prime (64778272679) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32389136304 + 32389136305.

It is an arithmetic number, because the mean of its divisors is an integer number (32389136305).

Almost surely, 2^64778272609 is an apocalyptic number.

It is an amenable number.

64778272609 is a deficient number, since it is larger than the sum of its proper divisors (1).

64778272609 is an equidigital number, since it uses as much as digits as its factorization.

64778272609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 14224896, while the sum is 58.

The spelling of 64778272609 in words is "sixty-four billion, seven hundred seventy-eight million, two hundred seventy-two thousand, six hundred nine".