63257731781 has 2 divisors, whose sum is σ = 63257731782. Its totient is φ = 63257731780.

The previous prime is 63257731739. The next prime is 63257731861. The reversal of 63257731781 is 18713775236.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 60484024225 + 2773707556 = 245935^2 + 52666^2 .

It is a cyclic number.

It is not a de Polignac number, because 63257731781 - 2⁶ = 63257731717 is a prime.

It is a super-2 number, since 2×63257731781² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (63257731711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 31628865890 + 31628865891.

It is an arithmetic number, because the mean of its divisors is an integer number (31628865891).

Almost surely, 2^63257731781 is an apocalyptic number.

It is an amenable number.

63257731781 is a deficient number, since it is larger than the sum of its proper divisors (1).

63257731781 is an equidigital number, since it uses as much as digits as its factorization.

63257731781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1481760, while the sum is 50.

The spelling of 63257731781 in words is "sixty-three billion, two hundred fifty-seven million, seven hundred thirty-one thousand, seven hundred eighty-one".