61687 has 2 divisors, whose sum is σ = 61688. Its totient is φ = 61686.

The previous prime is 61681. The next prime is 61703. The reversal of 61687 is 78616.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 61687 - 2⁷ = 61559 is a prime.

It is a Chen prime.

61687 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61681) 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, 30843 + 30844.

It is an arithmetic number, because the mean of its divisors is an integer number (30844).

2⁶¹⁶⁸⁷ is an apocalyptic number.

61687 is a deficient number, since it is larger than the sum of its proper divisors (1).

61687 is an equidigital number, since it uses as much as digits as its factorization.

61687 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2016, while the sum is 28.

The square root of 61687 is about 248.3686775743. The cubic root of 61687 is about 39.5122004720.

It can be divided in two parts, 616 and 87, that added together give a triangular number (703 = T₃₇).

The spelling of 61687 in words is "sixty-one thousand, six hundred eighty-seven".