1664705493 has 32 divisors (see below), whose sum is σ = 2756073600. Its totient is φ = 984297600.

The previous prime is 1664705479. The next prime is 1664705507. The reversal of 1664705493 is 3945074661.

1664705493 is a `hidden beast` number, since 1 + 66 + 47 + 0 + 549 + 3 = 666.

It is an interprime number because it is at equal distance from previous prime (1664705479) and next prime (1664705507).

It is not a de Polignac number, because 1664705493 - 2⁶ = 1664705429 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1664705423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 56178 + ... + 80531.

It is an arithmetic number, because the mean of its divisors is an integer number (86127300).

Almost surely, 2^1664705493 is an apocalyptic number.

It is an amenable number.

1664705493 is a deficient number, since it is larger than the sum of its proper divisors (1091368107).

1664705493 is a wasteful number, since it uses less digits than its factorization.

1664705493 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136770 (or 136764 counting only the distinct ones).

The product of its (nonzero) digits is 544320, while the sum is 45.

The square root of 1664705493 is about 40800.8026023999. The cubic root of 1664705493 is about 1185.1658732713.

The spelling of 1664705493 in words is "one billion, six hundred sixty-four million, seven hundred five thousand, four hundred ninety-three".