61517909 has 2 divisors, whose sum is σ = 61517910. Its totient is φ = 61517908.

The previous prime is 61517887. The next prime is 61517921. The reversal of 61517909 is 90971516.

61517909 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 42941809 + 18576100 = 6553^2 + 4310^2 .

It is a cyclic number.

It is not a de Polignac number, because 61517909 - 2⁸ = 61517653 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61517969) 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, 30758954 + 30758955.

It is an arithmetic number, because the mean of its divisors is an integer number (30758955).

Almost surely, 2^61517909 is an apocalyptic number.

It is an amenable number.

61517909 is a deficient number, since it is larger than the sum of its proper divisors (1).

61517909 is an equidigital number, since it uses as much as digits as its factorization.

61517909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 17010, while the sum is 38.

The square root of 61517909 is about 7843.3353237000. The cubic root of 61517909 is about 394.7606497394.

It can be divided in two parts, 61517 and 909, that added together give a palindrome (62426).

The spelling of 61517909 in words is "sixty-one million, five hundred seventeen thousand, nine hundred nine".