1664428841 has 2 divisors, whose sum is σ = 1664428842. Its totient is φ = 1664428840.

The previous prime is 1664428837. The next prime is 1664428847. The reversal of 1664428841 is 1488244661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1154572441 + 509856400 = 33979^2 + 22580^2 .

It is an emirp because it is prime and its reverse (1488244661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1664428841 - 2² = 1664428837 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1664428792 and 1664428801.

It is not a weakly prime, because it can be changed into another prime (1664428847) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 832214420 + 832214421.

It is an arithmetic number, because the mean of its divisors is an integer number (832214421).

Almost surely, 2^1664428841 is an apocalyptic number.

It is an amenable number.

1664428841 is a deficient number, since it is larger than the sum of its proper divisors (1).

1664428841 is an equidigital number, since it uses as much as digits as its factorization.

1664428841 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 294912, while the sum is 44.

The square root of 1664428841 is about 40797.4121850884. The cubic root of 1664428841 is about 1185.1002166782.

The spelling of 1664428841 in words is "one billion, six hundred sixty-four million, four hundred twenty-eight thousand, eight hundred forty-one".