64478731 has 2 divisors, whose sum is σ = 64478732. Its totient is φ = 64478730.

The previous prime is 64478717. The next prime is 64478737. The reversal of 64478731 is 13787446.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 64478731 - 2⁵ = 64478699 is a prime.

It is a super-2 number, since 2×64478731² = 8315013502740722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (64478737) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32239365 + 32239366.

It is an arithmetic number, because the mean of its divisors is an integer number (32239366).

Almost surely, 2^64478731 is an apocalyptic number.

64478731 is a deficient number, since it is larger than the sum of its proper divisors (1).

64478731 is an equidigital number, since it uses as much as digits as its factorization.

64478731 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 112896, while the sum is 40.

The square root of 64478731 is about 8029.8649428244. The cubic root of 64478731 is about 400.9948797343.

The spelling of 64478731 in words is "sixty-four million, four hundred seventy-eight thousand, seven hundred thirty-one".