61257807649 has 2 divisors, whose sum is σ = 61257807650. Its totient is φ = 61257807648.

The previous prime is 61257807619. The next prime is 61257807733. The reversal of 61257807649 is 94670875216.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 54802810000 + 6454997649 = 234100^2 + 80343^2 .

It is a cyclic number.

It is not a de Polignac number, because 61257807649 - 2¹¹ = 61257805601 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 61257807649.

It is not a weakly prime, because it can be changed into another prime (61257807619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30628903824 + 30628903825.

It is an arithmetic number, because the mean of its divisors is an integer number (30628903825).

Almost surely, 2^61257807649 is an apocalyptic number.

It is an amenable number.

61257807649 is a deficient number, since it is larger than the sum of its proper divisors (1).

61257807649 is an equidigital number, since it uses as much as digits as its factorization.

61257807649 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5080320, while the sum is 55.

The spelling of 61257807649 in words is "sixty-one billion, two hundred fifty-seven million, eight hundred seven thousand, six hundred forty-nine".