61043909257 has 2 divisors, whose sum is σ = 61043909258. Its totient is φ = 61043909256.

The previous prime is 61043909249. The next prime is 61043909263. The reversal of 61043909257 is 75290934016.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 60935416201 + 108493056 = 246851^2 + 10416^2 .

It is a cyclic number.

It is not a de Polignac number, because 61043909257 - 2³ = 61043909249 is a prime.

It is not a weakly prime, because it can be changed into another prime (61043909237) 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 as a sum of consecutive naturals, namely, 30521954628 + 30521954629.

It is an arithmetic number, because the mean of its divisors is an integer number (30521954629).

Almost surely, 2^61043909257 is an apocalyptic number.

It is an amenable number.

61043909257 is a deficient number, since it is larger than the sum of its proper divisors (1).

61043909257 is an equidigital number, since it uses as much as digits as its factorization.

61043909257 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 408240, while the sum is 46.

The spelling of 61043909257 in words is "sixty-one billion, forty-three million, nine hundred nine thousand, two hundred fifty-seven".