61043909209 has 2 divisors, whose sum is σ = 61043909210. Its totient is φ = 61043909208.

The previous prime is 61043909177. The next prime is 61043909231. The reversal of 61043909209 is 90290934016.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 36606403584 + 24437505625 = 191328^2 + 156325^2 .

It is a cyclic number.

It is not a de Polignac number, because 61043909209 - 2⁵ = 61043909177 is a prime.

It is not a weakly prime, because it can be changed into another prime (61043909249) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30521954604 + 30521954605.

It is an arithmetic number, because the mean of its divisors is an integer number (30521954605).

Almost surely, 2^61043909209 is an apocalyptic number.

It is an amenable number.

61043909209 is a deficient number, since it is larger than the sum of its proper divisors (1).

61043909209 is an equidigital number, since it uses as much as digits as its factorization.

61043909209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 104976, while the sum is 43.

The spelling of 61043909209 in words is "sixty-one billion, forty-three million, nine hundred nine thousand, two hundred nine".