64581481 has 2 divisors, whose sum is σ = 64581482. Its totient is φ = 64581480.

The previous prime is 64581457. The next prime is 64581499. The reversal of 64581481 is 18418546.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 63744256 + 837225 = 7984^2 + 915^2 .

It is a cyclic number.

It is not a de Polignac number, because 64581481 - 2¹⁷ = 64450409 is a prime.

It is a super-2 number, since 2×64581481² = 8341535376306722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 64581481.

It is not a weakly prime, because it can be changed into another prime (64581581) 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, 32290740 + 32290741.

It is an arithmetic number, because the mean of its divisors is an integer number (32290741).

Almost surely, 2^64581481 is an apocalyptic number.

It is an amenable number.

64581481 is a deficient number, since it is larger than the sum of its proper divisors (1).

64581481 is an equidigital number, since it uses as much as digits as its factorization.

64581481 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30720, while the sum is 37.

The square root of 64581481 is about 8036.2603865231. The cubic root of 64581481 is about 401.2077683189.

The spelling of 64581481 in words is "sixty-four million, five hundred eighty-one thousand, four hundred eighty-one".