61755809 has 2 divisors, whose sum is σ = 61755810. Its totient is φ = 61755808.

The previous prime is 61755797. The next prime is 61755823. The reversal of 61755809 is 90855716.

61755809 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 56670784 + 5085025 = 7528^2 + 2255^2 .

It is a cyclic number.

It is not a de Polignac number, because 61755809 - 2¹² = 61751713 is a prime.

It is not a weakly prime, because it can be changed into another prime (61754809) 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, 30877904 + 30877905.

It is an arithmetic number, because the mean of its divisors is an integer number (30877905).

Almost surely, 2^61755809 is an apocalyptic number.

It is an amenable number.

61755809 is a deficient number, since it is larger than the sum of its proper divisors (1).

61755809 is an equidigital number, since it uses as much as digits as its factorization.

61755809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 75600, while the sum is 41.

The square root of 61755809 is about 7858.4864318773. The cubic root of 61755809 is about 395.2688635790.

The spelling of 61755809 in words is "sixty-one million, seven hundred fifty-five thousand, eight hundred nine".