16666231 has 2 divisors, whose sum is σ = 16666232. Its totient is φ = 16666230.

The previous prime is 16666219. The next prime is 16666267. The reversal of 16666231 is 13266661.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 16666231 - 2¹⁹ = 16141943 is a prime.

It is a super-2 number, since 2×16666231² = 555526511490722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 16666193 and 16666202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16666201) 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, 8333115 + 8333116.

It is an arithmetic number, because the mean of its divisors is an integer number (8333116).

Almost surely, 2^16666231 is an apocalyptic number.

16666231 is a deficient number, since it is larger than the sum of its proper divisors (1).

16666231 is an equidigital number, since it uses as much as digits as its factorization.

16666231 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7776, while the sum is 31.

The square root of 16666231 is about 4082.4295462384. The cubic root of 16666231 is about 255.4342517420.

It can be divided in two parts, 1666 and 6231, that multiplied together give a triangular number (10380846 = T₄₅₅₆).

The spelling of 16666231 in words is "sixteen million, six hundred sixty-six thousand, two hundred thirty-one".