71861 has 2 divisors, whose sum is σ = 71862. Its totient is φ = 71860.

The previous prime is 71849. The next prime is 71867. The reversal of 71861 is 16817.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 37636 + 34225 = 194^2 + 185^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-71861 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71867) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35930 + 35931.

It is an arithmetic number, because the mean of its divisors is an integer number (35931).

2⁷¹⁸⁶¹ is an apocalyptic number.

It is an amenable number.

71861 is a deficient number, since it is larger than the sum of its proper divisors (1).

71861 is an equidigital number, since it uses as much as digits as its factorization.

71861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 336, while the sum is 23.

The square root of 71861 is about 268.0690209629. The cubic root of 71861 is about 41.5748877654.

The spelling of 71861 in words is "seventy-one thousand, eight hundred sixty-one".