1664625 has 32 divisors (see below), whose sum is σ = 2905344. Its totient is φ = 844800.

The previous prime is 1664569. The next prime is 1664627. The reversal of 1664625 is 5264661.

It is not a de Polignac number, because 1664625 - 2⁶ = 1664561 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1664592 and 1664601.

It is not an unprimeable number, because it can be changed into a prime (1664627) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8529 + ... + 8721.

It is an arithmetic number, because the mean of its divisors is an integer number (90792).

2^1664625 is an apocalyptic number.

1664625 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1664625 is the 690-th nonagonal number.

It is an amenable number.

1664625 is a deficient number, since it is larger than the sum of its proper divisors (1240719).

1664625 is a wasteful number, since it uses less digits than its factorization.

1664625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 234 (or 224 counting only the distinct ones).

The product of its digits is 8640, while the sum is 30.

The square root of 1664625 is about 1290.2034723252. The cubic root of 1664625 is about 118.5146770975.

The spelling of 1664625 in words is "one million, six hundred sixty-four thousand, six hundred twenty-five".