64427729 has 2 divisors, whose sum is σ = 64427730. Its totient is φ = 64427728.

The previous prime is 64427719. The next prime is 64427731. The reversal of 64427729 is 92772446.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 62331025 + 2096704 = 7895^2 + 1448^2 .

It is a cyclic number.

It is not a de Polignac number, because 64427729 - 2¹² = 64423633 is a prime.

It is a Sophie Germain prime.

Together with 64427731, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (64427719) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32213864 + 32213865.

It is an arithmetic number, because the mean of its divisors is an integer number (32213865).

Almost surely, 2^64427729 is an apocalyptic number.

It is an amenable number.

64427729 is a deficient number, since it is larger than the sum of its proper divisors (1).

64427729 is an equidigital number, since it uses as much as digits as its factorization.

64427729 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 169344, while the sum is 41.

The square root of 64427729 is about 8026.6885450975. The cubic root of 64427729 is about 400.8891242641.

It can be divided in two parts, 64427 and 729, that added together give a palindrome (65156).

The spelling of 64427729 in words is "sixty-four million, four hundred twenty-seven thousand, seven hundred twenty-nine".