1664509523 has 2 divisors, whose sum is σ = 1664509524. Its totient is φ = 1664509522.

The previous prime is 1664509499. The next prime is 1664509537. The reversal of 1664509523 is 3259054661.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1664509523 - 2¹⁰ = 1664508499 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (1664506523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 832254761 + 832254762.

It is an arithmetic number, because the mean of its divisors is an integer number (832254762).

Almost surely, 2^1664509523 is an apocalyptic number.

1664509523 is a deficient number, since it is larger than the sum of its proper divisors (1).

1664509523 is an equidigital number, since it uses as much as digits as its factorization.

1664509523 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 194400, while the sum is 41.

The square root of 1664509523 is about 40798.4009858230. The cubic root of 1664509523 is about 1185.1193653311.

The spelling of 1664509523 in words is "one billion, six hundred sixty-four million, five hundred nine thousand, five hundred twenty-three".