61286943889 has 2 divisors, whose sum is σ = 61286943890. Its totient is φ = 61286943888.

The previous prime is 61286943881. The next prime is 61286943929. The reversal of 61286943889 is 98834968216.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 53932166289 + 7354777600 = 232233^2 + 85760^2 .

It is a cyclic number.

It is not a de Polignac number, because 61286943889 - 2³ = 61286943881 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 61286943889.

It is not a weakly prime, because it can be changed into another prime (61286943881) 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, 30643471944 + 30643471945.

It is an arithmetic number, because the mean of its divisors is an integer number (30643471945).

Almost surely, 2^61286943889 is an apocalyptic number.

It is an amenable number.

61286943889 is a deficient number, since it is larger than the sum of its proper divisors (1).

61286943889 is an equidigital number, since it uses as much as digits as its factorization.

61286943889 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 35831808, while the sum is 64.

The spelling of 61286943889 in words is "sixty-one billion, two hundred eighty-six million, nine hundred forty-three thousand, eight hundred eighty-nine".