1664816905 has 16 divisors (see below), whose sum is σ = 2024253504. Its totient is φ = 1314243520.

The previous prime is 1664816897. The next prime is 1664816911. The reversal of 1664816905 is 5096184661.

It is not a de Polignac number, because 1664816905 - 2³ = 1664816897 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 450927 + ... + 454603.

It is an arithmetic number, because the mean of its divisors is an integer number (126515844).

Almost surely, 2^1664816905 is an apocalyptic number.

It is an amenable number.

1664816905 is a deficient number, since it is larger than the sum of its proper divisors (359436599).

1664816905 is a wasteful number, since it uses less digits than its factorization.

1664816905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4856.

The product of its (nonzero) digits is 311040, while the sum is 46.

The square root of 1664816905 is about 40802.1678958361. The cubic root of 1664816905 is about 1185.1923121330.

The spelling of 1664816905 in words is "one billion, six hundred sixty-four million, eight hundred sixteen thousand, nine hundred five".