63798916421 has 2 divisors, whose sum is σ = 63798916422. Its totient is φ = 63798916420.

The previous prime is 63798916397. The next prime is 63798916457. The reversal of 63798916421 is 12461989736.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 63599796100 + 199120321 = 252190^2 + 14111^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-63798916421 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (63798916121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 31899458210 + 31899458211.

It is an arithmetic number, because the mean of its divisors is an integer number (31899458211).

Almost surely, 2^63798916421 is an apocalyptic number.

It is an amenable number.

63798916421 is a deficient number, since it is larger than the sum of its proper divisors (1).

63798916421 is an equidigital number, since it uses as much as digits as its factorization.

63798916421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3919104, while the sum is 56.

The spelling of 63798916421 in words is "sixty-three billion, seven hundred ninety-eight million, nine hundred sixteen thousand, four hundred twenty-one".