61783561913 has 2 divisors, whose sum is σ = 61783561914. Its totient is φ = 61783561912.

The previous prime is 61783561909. The next prime is 61783561919. The reversal of 61783561913 is 31916538716.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 53126562064 + 8656999849 = 230492^2 + 93043^2 .

It is a cyclic number.

It is not a de Polignac number, because 61783561913 - 2² = 61783561909 is a prime.

It is not a weakly prime, because it can be changed into another prime (61783561919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30891780956 + 30891780957.

It is an arithmetic number, because the mean of its divisors is an integer number (30891780957).

Almost surely, 2^61783561913 is an apocalyptic number.

It is an amenable number.

61783561913 is a deficient number, since it is larger than the sum of its proper divisors (1).

61783561913 is an equidigital number, since it uses as much as digits as its factorization.

61783561913 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 816480, while the sum is 50.

The spelling of 61783561913 in words is "sixty-one billion, seven hundred eighty-three million, five hundred sixty-one thousand, nine hundred thirteen".