1664916625 has 16 divisors (see below), whose sum is σ = 2079043200. Its totient is φ = 1331146800.

The previous prime is 1664916581. The next prime is 1664916637. The reversal of 1664916625 is 5266194661.

It is a de Polignac number, because none of the positive numbers 2^k-1664916625 is a prime.

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, 305676 + ... + 311074.

It is an arithmetic number, because the mean of its divisors is an integer number (129940200).

Almost surely, 2^1664916625 is an apocalyptic number.

It is an amenable number.

1664916625 is a deficient number, since it is larger than the sum of its proper divisors (414126575).

1664916625 is an equidigital number, since it uses as much as digits as its factorization.

1664916625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7881 (or 7871 counting only the distinct ones).

The product of its digits is 466560, while the sum is 46.

The square root of 1664916625 is about 40803.3898714310. The cubic root of 1664916625 is about 1185.2159753994.

The spelling of 1664916625 in words is "one billion, six hundred sixty-four million, nine hundred sixteen thousand, six hundred twenty-five".