1806631 has 2 divisors, whose sum is σ = 1806632. Its totient is φ = 1806630.

The previous prime is 1806617. The next prime is 1806643. The reversal of 1806631 is 1366081.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1806631 - 2⁷ = 1806503 is a prime.

It is a super-2 number, since 2×1806631² = 6527831140322, which contains 22 as substring.

1806631 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 1806596 and 1806605.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1806031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 903315 + 903316.

It is an arithmetic number, because the mean of its divisors is an integer number (903316).

2^1806631 is an apocalyptic number.

1806631 is a deficient number, since it is larger than the sum of its proper divisors (1).

1806631 is an equidigital number, since it uses as much as digits as its factorization.

1806631 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 1806631 is about 1344.1097425434. The cubic root of 1806631 is about 121.7932312354.

The spelling of 1806631 in words is "one million, eight hundred six thousand, six hundred thirty-one".