61861 has 2 divisors, whose sum is σ = 61862.
Its totient is φ = 61860.
The previous prime is 61843. The next prime is 61871. The reversal of 61861 is 16816.
It is a strong prime.
It can be written as a sum of positive squares in only one way, i.e., 50625 + 11236 = 225^2 + 106^2
It is a cyclic number.
It is a de Polignac number, because none of the positive numbers 2k-61861 is a prime.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (61871) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30930 + 30931.
It is an arithmetic number, because the mean of its divisors is an integer number (30931).
261861 is an apocalyptic number.
It is an amenable number.
61861 is a deficient number, since it is larger than the sum of its proper divisors (1).
61861 is an equidigital number, since it uses as much as digits as its factorization.
61861 is an odious number, because the sum of its binary digits is odd.
The product of its digits is 288, while the sum is 22.
The square root of 61861 is about 248.7187166258.
The cubic root of 61861 is about 39.5493161733.
The spelling of 61861 in words is "sixty-one thousand, eight hundred sixty-one".