63104187721 has 2 divisors, whose sum is σ = 63104187722. Its totient is φ = 63104187720.

The previous prime is 63104187673. The next prime is 63104187761. The reversal of 63104187721 is 12778140136.

It is a happy number.

It is an a-pointer prime, because the next prime (63104187761) can be obtained adding 63104187721 to its sum of digits (40).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 46395006025 + 16709181696 = 215395^2 + 129264^2 .

It is a cyclic number.

It is not a de Polignac number, because 63104187721 - 2³¹ = 60956704073 is a prime.

It is not a weakly prime, because it can be changed into another prime (63104187761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 31552093860 + 31552093861.

It is an arithmetic number, because the mean of its divisors is an integer number (31552093861).

Almost surely, 2^63104187721 is an apocalyptic number.

It is an amenable number.

63104187721 is a deficient number, since it is larger than the sum of its proper divisors (1).

63104187721 is an equidigital number, since it uses as much as digits as its factorization.

63104187721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 56448, while the sum is 40.

The spelling of 63104187721 in words is "sixty-three billion, one hundred four million, one hundred eighty-seven thousand, seven hundred twenty-one".