1664005265 has 24 divisors (see below), whose sum is σ = 2256258240. Its totient is φ = 1175363904.

The previous prime is 1664005241. The next prime is 1664005283. The reversal of 1664005265 is 5625004661.

It is not a de Polignac number, because 1664005265 - 2¹⁰ = 1664004241 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 23375 + ... + 62244.

It is an arithmetic number, because the mean of its divisors is an integer number (94010760).

Almost surely, 2^1664005265 is an apocalyptic number.

It is an amenable number.

1664005265 is a deficient number, since it is larger than the sum of its proper divisors (592252975).

1664005265 is a wasteful number, since it uses less digits than its factorization.

1664005265 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85673 (or 85660 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 35.

The square root of 1664005265 is about 40792.2206431569. The cubic root of 1664005265 is about 1184.9996771647. Note that the first 3 decimals are identical.

The spelling of 1664005265 in words is "one billion, six hundred sixty-four million, five thousand, two hundred sixty-five".