64438139977 has 2 divisors, whose sum is σ = 64438139978. Its totient is φ = 64438139976.

The previous prime is 64438139959. The next prime is 64438139993. The reversal of 64438139977 is 77993183446.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 44479231801 + 19958908176 = 210901^2 + 141276^2 .

It is a cyclic number.

It is not a de Polignac number, because 64438139977 - 2⁷ = 64438139849 is a prime.

It is not a weakly prime, because it can be changed into another prime (64438139177) 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, 32219069988 + 32219069989.

It is an arithmetic number, because the mean of its divisors is an integer number (32219069989).

Almost surely, 2^64438139977 is an apocalyptic number.

It is an amenable number.

64438139977 is a deficient number, since it is larger than the sum of its proper divisors (1).

64438139977 is an equidigital number, since it uses as much as digits as its factorization.

64438139977 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 27433728, while the sum is 61.

The spelling of 64438139977 in words is "sixty-four billion, four hundred thirty-eight million, one hundred thirty-nine thousand, nine hundred seventy-seven".