63865000781 has 2 divisors, whose sum is σ = 63865000782. Its totient is φ = 63865000780.

The previous prime is 63865000757. The next prime is 63865000783. The reversal of 63865000781 is 18700056836.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 59604827881 + 4260172900 = 244141^2 + 65270^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-63865000781 is a prime.

It is a super-2 number, since 2×63865000781² (a number of 22 digits) contains 22 as substring.

It is a Sophie Germain prime.

Together with 63865000783, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (63865000783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 31932500390 + 31932500391.

It is an arithmetic number, because the mean of its divisors is an integer number (31932500391).

Almost surely, 2^63865000781 is an apocalyptic number.

It is an amenable number.

63865000781 is a deficient number, since it is larger than the sum of its proper divisors (1).

63865000781 is an equidigital number, since it uses as much as digits as its factorization.

63865000781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 241920, while the sum is 44.

The spelling of 63865000781 in words is "sixty-three billion, eight hundred sixty-five million, seven hundred eighty-one", and thus it is an aban number.