1664143841 has 4 divisors (see below), whose sum is σ = 1664256000. Its totient is φ = 1664031684.

The previous prime is 1664143837. The next prime is 1664143853. The reversal of 1664143841 is 1483414661.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 1664143841 - 2² = 1664143837 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1664143795 and 1664143804.

It is not an unprimeable number, because it can be changed into a prime (1664142841) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29681 + ... + 64878.

It is an arithmetic number, because the mean of its divisors is an integer number (416064000).

Almost surely, 2^1664143841 is an apocalyptic number.

It is an amenable number.

1664143841 is a deficient number, since it is larger than the sum of its proper divisors (112159).

1664143841 is an equidigital number, since it uses as much as digits as its factorization.

1664143841 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112158.

The product of its digits is 55296, while the sum is 38.

The square root of 1664143841 is about 40793.9191669543. The cubic root of 1664143841 is about 1185.0325712827.

The spelling of 1664143841 in words is "one billion, six hundred sixty-four million, one hundred forty-three thousand, eight hundred forty-one".