61615909 has 2 divisors, whose sum is σ = 61615910. Its totient is φ = 61615908.

The previous prime is 61615889. The next prime is 61615913. The reversal of 61615909 is 90951616.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 33895684 + 27720225 = 5822^2 + 5265^2 .

It is a cyclic number.

It is not a de Polignac number, because 61615909 - 2¹¹ = 61613861 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61615969) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30807954 + 30807955.

It is an arithmetic number, because the mean of its divisors is an integer number (30807955).

Almost surely, 2^61615909 is an apocalyptic number.

It is an amenable number.

61615909 is a deficient number, since it is larger than the sum of its proper divisors (1).

61615909 is an equidigital number, since it uses as much as digits as its factorization.

61615909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14580, while the sum is 37.

The square root of 61615909 is about 7849.5801798568. The cubic root of 61615909 is about 394.9701606472.

The spelling of 61615909 in words is "sixty-one million, six hundred fifteen thousand, nine hundred nine".