61311743989 has 2 divisors, whose sum is σ = 61311743990. Its totient is φ = 61311743988.

The previous prime is 61311743963. The next prime is 61311744017. The reversal of 61311743989 is 98934711316.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 61284963364 + 26780625 = 247558^2 + 5175^2 .

It is a cyclic number.

It is not a de Polignac number, because 61311743989 - 2⁷ = 61311743861 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61311743939) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30655871994 + 30655871995.

It is an arithmetic number, because the mean of its divisors is an integer number (30655871995).

Almost surely, 2^61311743989 is an apocalyptic number.

It is an amenable number.

61311743989 is a deficient number, since it is larger than the sum of its proper divisors (1).

61311743989 is an equidigital number, since it uses as much as digits as its factorization.

61311743989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 979776, while the sum is 52.

The spelling of 61311743989 in words is "sixty-one billion, three hundred eleven million, seven hundred forty-three thousand, nine hundred eighty-nine".