61608181817 has 24 divisors (see below), whose sum is σ = 77195554632. Its totient is φ = 48734784000.

The previous prime is 61608181783. The next prime is 61608181847. The reversal of 61608181817 is 71818180616.

It can be written as a sum of positive squares in 4 ways, for example, as 1675756096 + 59932425721 = 40936^2 + 244811^2 .

It is not a de Polignac number, because 61608181817 - 2⁸ = 61608181561 is a prime.

It is not an unprimeable number, because it can be changed into a prime (61608181847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5026817 + ... + 5039057.

It is an arithmetic number, because the mean of its divisors is an integer number (3216481443).

Almost surely, 2^61608181817 is an apocalyptic number.

It is an amenable number.

61608181817 is a deficient number, since it is larger than the sum of its proper divisors (15587372815).

61608181817 is a wasteful number, since it uses less digits than its factorization.

61608181817 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20169 (or 20162 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 47.

The spelling of 61608181817 in words is "sixty-one billion, six hundred eight million, one hundred eighty-one thousand, eight hundred seventeen".