634903019561 has 2 divisors, whose sum is σ = 634903019562. Its totient is φ = 634903019560.

The previous prime is 634903019503. The next prime is 634903019573. The reversal of 634903019561 is 165910309436.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 561984118336 + 72918901225 = 749656^2 + 270035^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-634903019561 is a prime.

It is not a weakly prime, because it can be changed into another prime (634903019591) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 317451509780 + 317451509781.

It is an arithmetic number, because the mean of its divisors is an integer number (317451509781).

Almost surely, 2^634903019561 is an apocalyptic number.

It is an amenable number.

634903019561 is a deficient number, since it is larger than the sum of its proper divisors (1).

634903019561 is an equidigital number, since it uses as much as digits as its factorization.

634903019561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 524880, while the sum is 47.

The spelling of 634903019561 in words is "six hundred thirty-four billion, nine hundred three million, nineteen thousand, five hundred sixty-one".