64731321 has 12 divisors (see below), whose sum is σ = 93660372. Its totient is φ = 43080576.

The previous prime is 64731311. The next prime is 64731341. The reversal of 64731321 is 12313746.

64731321 is a `hidden beast` number, since 647 + 3 + 13 + 2 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 20575296 + 44156025 = 4536^2 + 6645^2 .

It is not a de Polignac number, because 64731321 - 2²⁵ = 31176889 is a prime.

It is not an unprimeable number, because it can be changed into a prime (64731311) 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 in 11 ways as a sum of consecutive naturals, for example, 276 + ... + 11381.

It is an arithmetic number, because the mean of its divisors is an integer number (7805031).

Almost surely, 2^64731321 is an apocalyptic number.

It is an amenable number.

64731321 is a deficient number, since it is larger than the sum of its proper divisors (28929051).

64731321 is a wasteful number, since it uses less digits than its factorization.

64731321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12280 (or 12277 counting only the distinct ones).

The product of its digits is 3024, while the sum is 27.

The square root of 64731321 is about 8045.5777294114. The cubic root of 64731321 is about 401.5178186979.

The spelling of 64731321 in words is "sixty-four million, seven hundred thirty-one thousand, three hundred twenty-one".