61637813 has 2 divisors, whose sum is σ = 61637814. Its totient is φ = 61637812.

The previous prime is 61637809. The next prime is 61637857. The reversal of 61637813 is 31873616.

61637813 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., 57866449 + 3771364 = 7607^2 + 1942^2 .

It is a cyclic number.

It is not a de Polignac number, because 61637813 - 2² = 61637809 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61637113) 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, 30818906 + 30818907.

It is an arithmetic number, because the mean of its divisors is an integer number (30818907).

Almost surely, 2^61637813 is an apocalyptic number.

It is an amenable number.

61637813 is a deficient number, since it is larger than the sum of its proper divisors (1).

61637813 is an equidigital number, since it uses as much as digits as its factorization.

61637813 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18144, while the sum is 35.

The square root of 61637813 is about 7850.9752897331. The cubic root of 61637813 is about 395.0169580926.

The spelling of 61637813 in words is "sixty-one million, six hundred thirty-seven thousand, eight hundred thirteen".