61636889 has 2 divisors, whose sum is σ = 61636890. Its totient is φ = 61636888.

The previous prime is 61636877. The next prime is 61636891. The reversal of 61636889 is 98863616.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 44662489 + 16974400 = 6683^2 + 4120^2 .

It is a cyclic number.

It is not a de Polignac number, because 61636889 - 2⁸ = 61636633 is a prime.

Together with 61636891, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (61636819) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30818444 + 30818445.

It is an arithmetic number, because the mean of its divisors is an integer number (30818445).

Almost surely, 2^61636889 is an apocalyptic number.

It is an amenable number.

61636889 is a deficient number, since it is larger than the sum of its proper divisors (1).

61636889 is an equidigital number, since it uses as much as digits as its factorization.

61636889 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 373248, while the sum is 47.

The square root of 61636889 is about 7850.9164433205. The cubic root of 61636889 is about 395.0149842097.

The spelling of 61636889 in words is "sixty-one million, six hundred thirty-six thousand, eight hundred eighty-nine".