63910721947 has 2 divisors, whose sum is σ = 63910721948.
Its totient is φ = 63910721946.
The previous prime is 63910721939. The next prime is 63910722049. The reversal of 63910721947 is 74912701936.
63910721947 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.
It is a weak prime.
It is a cyclic number.
It is not a de Polignac number, because 63910721947 - 23 = 63910721939 is a prime.
It is a self number, because there is not a number n which added to its sum of digits gives 63910721947.
It is not a weakly prime, because it can be changed into another prime (63910701947) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 31955360973 + 31955360974.
It is an arithmetic number, because the mean of its divisors is an integer number (31955360974).
Almost surely, 263910721947 is an apocalyptic number.
63910721947 is a deficient number, since it is larger than the sum of its proper divisors (1).
63910721947 is an equidigital number, since it uses as much as digits as its factorization.
63910721947 is an evil number, because the sum of its binary digits is even.
The product of its (nonzero) digits is 571536, while the sum is 49.
The spelling of 63910721947 in words is "sixty-three billion, nine hundred ten million, seven hundred twenty-one thousand, nine hundred forty-seven".