866861519 has 2 divisors, whose sum is σ = 866861520. Its totient is φ = 866861518.

The previous prime is 866861509. The next prime is 866861531. The reversal of 866861519 is 915168668.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 866861519 - 2⁴ = 866861503 is a prime.

It is a super-2 number, since 2×866861519² = 1502897786245974722, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (866861509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433430759 + 433430760.

It is an arithmetic number, because the mean of its divisors is an integer number (433430760).

Almost surely, 2^866861519 is an apocalyptic number.

866861519 is a deficient number, since it is larger than the sum of its proper divisors (1).

866861519 is an equidigital number, since it uses as much as digits as its factorization.

866861519 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 622080, while the sum is 50.

The square root of 866861519 is about 29442.5121040987. The cubic root of 866861519 is about 953.4909489535.

The spelling of 866861519 in words is "eight hundred sixty-six million, eight hundred sixty-one thousand, five hundred nineteen".