108439861 has 2 divisors, whose sum is σ = 108439862. Its totient is φ = 108439860.

The previous prime is 108439853. The next prime is 108439879. The reversal of 108439861 is 168934801.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 107640625 + 799236 = 10375^2 + 894^2 .

It is a cyclic number.

It is not a de Polignac number, because 108439861 - 2³ = 108439853 is a prime.

It is equal to p_6218878 and since 108439861 and 6218878 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (108439801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 54219930 + 54219931.

It is an arithmetic number, because the mean of its divisors is an integer number (54219931).

Almost surely, 2^108439861 is an apocalyptic number.

It is an amenable number.

108439861 is a deficient number, since it is larger than the sum of its proper divisors (1).

108439861 is an equidigital number, since it uses as much as digits as its factorization.

108439861 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 41472, while the sum is 40.

The square root of 108439861 is about 10413.4461634946. The cubic root of 108439861 is about 476.8659545083.

The spelling of 108439861 in words is "one hundred eight million, four hundred thirty-nine thousand, eight hundred sixty-one".