64731281 has 2 divisors, whose sum is σ = 64731282. Its totient is φ = 64731280.

The previous prime is 64731263. The next prime is 64731283. The reversal of 64731281 is 18213746.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 64320400 + 410881 = 8020^2 + 641^2 .

It is a cyclic number.

It is not a de Polignac number, because 64731281 - 2²² = 60536977 is a prime.

It is a super-2 number, since 2×64731281² = 8380277479801922, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 64731283, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is equal to p_3825680 and since 64731281 and 3825680 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (64731283) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32365640 + 32365641.

It is an arithmetic number, because the mean of its divisors is an integer number (32365641).

Almost surely, 2^64731281 is an apocalyptic number.

It is an amenable number.

64731281 is a deficient number, since it is larger than the sum of its proper divisors (1).

64731281 is an equidigital number, since it uses as much as digits as its factorization.

64731281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8064, while the sum is 32.

The square root of 64731281 is about 8045.5752435733. The cubic root of 64731281 is about 401.5177359933.

The spelling of 64731281 in words is "sixty-four million, seven hundred thirty-one thousand, two hundred eighty-one".