20166631 has 2 divisors, whose sum is σ = 20166632. Its totient is φ = 20166630.

The previous prime is 20166617. The next prime is 20166637. The reversal of 20166631 is 13666102.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20166631 - 2⁹ = 20166119 is a prime.

It is a super-2 number, since 2×20166631² = 813386011780322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20166596 and 20166605.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20166637) 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, 10083315 + 10083316.

It is an arithmetic number, because the mean of its divisors is an integer number (10083316).

Almost surely, 2^20166631 is an apocalyptic number.

20166631 is a deficient number, since it is larger than the sum of its proper divisors (1).

20166631 is an equidigital number, since it uses as much as digits as its factorization.

20166631 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 20166631 is about 4490.7272239583. The cubic root of 20166631 is about 272.1935212711.

The spelling of 20166631 in words is "twenty million, one hundred sixty-six thousand, six hundred thirty-one".