64778629 has 2 divisors, whose sum is σ = 64778630. Its totient is φ = 64778628.

The previous prime is 64778627. The next prime is 64778689. The reversal of 64778629 is 92687746.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 57729604 + 7049025 = 7598^2 + 2655^2 .

It is a cyclic number.

It is not a de Polignac number, because 64778629 - 2¹ = 64778627 is a prime.

Together with 64778627, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64778621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32389314 + 32389315.

It is an arithmetic number, because the mean of its divisors is an integer number (32389315).

Almost surely, 2^64778629 is an apocalyptic number.

It is an amenable number.

64778629 is a deficient number, since it is larger than the sum of its proper divisors (1).

64778629 is an equidigital number, since it uses as much as digits as its factorization.

64778629 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1016064, while the sum is 49.

The square root of 64778629 is about 8048.5171926262. The cubic root of 64778629 is about 401.6156094795.

The spelling of 64778629 in words is "sixty-four million, seven hundred seventy-eight thousand, six hundred twenty-nine".