64522781 has 2 divisors, whose sum is σ = 64522782. Its totient is φ = 64522780.

The previous prime is 64522763. The next prime is 64522793. The reversal of 64522781 is 18722546.

64522781 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51984100 + 12538681 = 7210^2 + 3541^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-64522781 is a prime.

It is a super-2 number, since 2×64522781² = 8326378535947922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64522181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32261390 + 32261391.

It is an arithmetic number, because the mean of its divisors is an integer number (32261391).

Almost surely, 2^64522781 is an apocalyptic number.

It is an amenable number.

64522781 is a deficient number, since it is larger than the sum of its proper divisors (1).

64522781 is an equidigital number, since it uses as much as digits as its factorization.

64522781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 26880, while the sum is 35.

The square root of 64522781 is about 8032.6073600046. The cubic root of 64522781 is about 401.0861749735.

The spelling of 64522781 in words is "sixty-four million, five hundred twenty-two thousand, seven hundred eighty-one".