64778317 has 2 divisors, whose sum is σ = 64778318. Its totient is φ = 64778316.

The previous prime is 64778303. The next prime is 64778333. The reversal of 64778317 is 71387746.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 59274601 + 5503716 = 7699^2 + 2346^2 .

It is a cyclic number.

It is not a de Polignac number, because 64778317 - 2²³ = 56389709 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64778117) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32389158 + 32389159.

It is an arithmetic number, because the mean of its divisors is an integer number (32389159).

Almost surely, 2^64778317 is an apocalyptic number.

It is an amenable number.

64778317 is a deficient number, since it is larger than the sum of its proper divisors (1).

64778317 is an equidigital number, since it uses as much as digits as its factorization.

64778317 is an evil number, because the sum of its binary digits is even.

The product of its digits is 197568, while the sum is 43.

The square root of 64778317 is about 8048.4978101507. The cubic root of 64778317 is about 401.6149646975.

The spelling of 64778317 in words is "sixty-four million, seven hundred seventy-eight thousand, three hundred seventeen".