61686643 has 2 divisors, whose sum is σ = 61686644. Its totient is φ = 61686642.

The previous prime is 61686637. The next prime is 61686649. The reversal of 61686643 is 34668616.

It is a balanced prime because it is at equal distance from previous prime (61686637) and next prime (61686649).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61686643 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 61686596 and 61686605.

It is not a weakly prime, because it can be changed into another prime (61686649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30843321 + 30843322.

It is an arithmetic number, because the mean of its divisors is an integer number (30843322).

Almost surely, 2^61686643 is an apocalyptic number.

61686643 is a deficient number, since it is larger than the sum of its proper divisors (1).

61686643 is an equidigital number, since it uses as much as digits as its factorization.

61686643 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 124416, while the sum is 40.

The square root of 61686643 is about 7854.0844787919. The cubic root of 61686643 is about 395.1212424911.

The spelling of 61686643 in words is "sixty-one million, six hundred eighty-six thousand, six hundred forty-three".