1664466525 has 18 divisors (see below), whose sum is σ = 2981244890. Its totient is φ = 887715360.

The previous prime is 1664466499. The next prime is 1664466581. The reversal of 1664466525 is 5256644661.

1664466525 is a `hidden beast` number, since 1 + 6 + 64 + 4 + 66 + 525 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 188293284 + 1476173241 = 13722^2 + 38421^2 .

It is not a de Polignac number, because 1664466525 - 2⁵ = 1664466493 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 3698590 + ... + 3699039.

Almost surely, 2^1664466525 is an apocalyptic number.

1664466525 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1664466525 is a deficient number, since it is larger than the sum of its proper divisors (1316778365).

1664466525 is a wasteful number, since it uses less digits than its factorization.

1664466525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7397645 (or 7397637 counting only the distinct ones).

The product of its digits is 1036800, while the sum is 45.

The square root of 1664466525 is about 40797.8740254930. The cubic root of 1664466525 is about 1185.1091604829.

The spelling of 1664466525 in words is "one billion, six hundred sixty-four million, four hundred sixty-six thousand, five hundred twenty-five".