866666431 has 2 divisors, whose sum is σ = 866666432. Its totient is φ = 866666430.

The previous prime is 866666407. The next prime is 866666447. The reversal of 866666431 is 134666668.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 866666431 - 2¹⁷ = 866535359 is a prime.

It is a super-2 number, since 2×866666431² = 1502221405244555522, which contains 22 as substring.

It is a nialpdrome in base 10.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (866666461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433333215 + 433333216.

It is an arithmetic number, because the mean of its divisors is an integer number (433333216).

Almost surely, 2^866666431 is an apocalyptic number.

866666431 is a deficient number, since it is larger than the sum of its proper divisors (1).

866666431 is an equidigital number, since it uses as much as digits as its factorization.

866666431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 746496, while the sum is 46.

The square root of 866666431 is about 29439.1988851599. The cubic root of 866666431 is about 953.4194155755.

The spelling of 866666431 in words is "eight hundred sixty-six million, six hundred sixty-six thousand, four hundred thirty-one".