1664348661 has 16 divisors (see below), whose sum is σ = 2466933120. Its totient is φ = 1109011680.

The previous prime is 1664348659. The next prime is 1664348663. The reversal of 1664348661 is 1668434661.

1664348661 is a `hidden beast` number, since 166 + 4 + 3 + 486 + 6 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (1664348659) and next prime (1664348663).

It is not a de Polignac number, because 1664348661 - 2¹ = 1664348659 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1664348663) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 43816 + ... + 72446.

It is an arithmetic number, because the mean of its divisors is an integer number (154183320).

Almost surely, 2^1664348661 is an apocalyptic number.

It is an amenable number.

1664348661 is a deficient number, since it is larger than the sum of its proper divisors (802584459).

1664348661 is a wasteful number, since it uses less digits than its factorization.

1664348661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30793 (or 30787 counting only the distinct ones).

The product of its digits is 497664, while the sum is 45.

The square root of 1664348661 is about 40796.4295128875. The cubic root of 1664348661 is about 1185.0811865543.

The spelling of 1664348661 in words is "one billion, six hundred sixty-four million, three hundred forty-eight thousand, six hundred sixty-one".