64736863781 has 2 divisors, whose sum is σ = 64736863782. Its totient is φ = 64736863780.

The previous prime is 64736863739. The next prime is 64736863801. The reversal of 64736863781 is 18736863746.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 38177642881 + 26559220900 = 195391^2 + 162970^2 .

It is a cyclic number.

It is not a de Polignac number, because 64736863781 - 2⁶ = 64736863717 is a prime.

It is a super-2 number, since 2×64736863781² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 64736863781.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64736883781) 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, 32368431890 + 32368431891.

It is an arithmetic number, because the mean of its divisors is an integer number (32368431891).

Almost surely, 2^64736863781 is an apocalyptic number.

It is an amenable number.

64736863781 is a deficient number, since it is larger than the sum of its proper divisors (1).

64736863781 is an equidigital number, since it uses as much as digits as its factorization.

64736863781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24385536, while the sum is 59.

The spelling of 64736863781 in words is "sixty-four billion, seven hundred thirty-six million, eight hundred sixty-three thousand, seven hundred eighty-one".