866431 has 2 divisors, whose sum is σ = 866432. Its totient is φ = 866430.

The previous prime is 866417. The next prime is 866443. The reversal of 866431 is 134668.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 866431 - 2⁵ = 866399 is a prime.

It is a super-2 number, since 2×866431² = 1501405355522, which contains 22 as substring.

866431 is a lucky number.

It is a nialpdrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 866431.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (866461) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433215 + 433216.

It is an arithmetic number, because the mean of its divisors is an integer number (433216).

2⁸⁶⁶⁴³¹ is an apocalyptic number.

866431 is a deficient number, since it is larger than the sum of its proper divisors (1).

866431 is an equidigital number, since it uses as much as digits as its factorization.

866431 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3456, while the sum is 28.

The square root of 866431 is about 930.8227543416. The cubic root of 866431 is about 95.3333075239. Note that the first 4 decimals are identical.

The spelling of 866431 in words is "eight hundred sixty-six thousand, four hundred thirty-one".