1664025040 has 20 divisors (see below), whose sum is σ = 3868858404. Its totient is φ = 665609984.

The previous prime is 1664025031. The next prime is 1664025053. The reversal of 1664025040 is 405204661.

It can be written as a sum of positive squares in 2 ways, for example, as 183006784 + 1481018256 = 13528^2 + 38484^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10400077 + ... + 10400236.

Almost surely, 2^1664025040 is an apocalyptic number.

1664025040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1664025040 is an abundant number, since it is smaller than the sum of its proper divisors (2204833364).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1664025040 is a wasteful number, since it uses less digits than its factorization.

1664025040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20800326 (or 20800320 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 28.

The square root of 1664025040 is about 40792.4630293391. The cubic root of 1664025040 is about 1185.0043713156.

The spelling of 1664025040 in words is "one billion, six hundred sixty-four million, twenty-five thousand, forty".