1664431 has 2 divisors, whose sum is σ = 1664432. Its totient is φ = 1664430.

The previous prime is 1664417. The next prime is 1664437. The reversal of 1664431 is 1344661.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1664431 - 2⁹ = 1663919 is a prime.

It is a super-2 number, since 2×1664431² = 5540661107522, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1664396 and 1664405.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1664437) by changing a digit.

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

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 832215 + 832216.

It is an arithmetic number, because the mean of its divisors is an integer number (832216).

2^1664431 is an apocalyptic number.

1664431 is a deficient number, since it is larger than the sum of its proper divisors (1).

1664431 is an equidigital number, since it uses as much as digits as its factorization.

1664431 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1728, while the sum is 25.

The square root of 1664431 is about 1290.1282881946. The cubic root of 1664431 is about 118.5100729092.

The spelling of 1664431 in words is "one million, six hundred sixty-four thousand, four hundred thirty-one".