16865813 has 2 divisors, whose sum is σ = 16865814. Its totient is φ = 16865812.

The previous prime is 16865777. The next prime is 16865851. The reversal of 16865813 is 31856861.

It is a happy number.

It is an a-pointer prime, because the next prime (16865851) can be obtained adding 16865813 to its sum of digits (38).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10804369 + 6061444 = 3287^2 + 2462^2 .

It is a cyclic number.

It is not a de Polignac number, because 16865813 - 2⁸ = 16865557 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16865213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8432906 + 8432907.

It is an arithmetic number, because the mean of its divisors is an integer number (8432907).

Almost surely, 2^16865813 is an apocalyptic number.

It is an amenable number.

16865813 is a deficient number, since it is larger than the sum of its proper divisors (1).

16865813 is an equidigital number, since it uses as much as digits as its factorization.

16865813 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 34560, while the sum is 38.

The square root of 16865813 is about 4106.8008230251. The cubic root of 16865813 is about 256.4498367401.

The spelling of 16865813 in words is "sixteen million, eight hundred sixty-five thousand, eight hundred thirteen".