1664576388 has 18 divisors (see below), whose sum is σ = 4207679294. Its totient is φ = 554858784.

The previous prime is 1664576383. The next prime is 1664576399. The reversal of 1664576388 is 8836754661.

1664576388 is a `hidden beast` number, since 1 + 6 + 64 + 576 + 3 + 8 + 8 = 666.

1664576388 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 1452524544 + 212051844 = 38112^2 + 14562^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-3 number, since 3×1664576388³ (a number of 29 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (1664576383) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 23119081 + ... + 23119152.

Almost surely, 2^1664576388 is an apocalyptic number.

1664576388 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

1664576388 is an abundant number, since it is smaller than the sum of its proper divisors (2543102906).

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

1664576388 is a wasteful number, since it uses less digits than its factorization.

1664576388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46238243 (or 46238238 counting only the distinct ones).

The product of its digits is 5806080, while the sum is 54.

The square root of 1664576388 is about 40799.2204337289. The cubic root of 1664576388 is about 1185.1352342591.

The spelling of 1664576388 in words is "one billion, six hundred sixty-four million, five hundred seventy-six thousand, three hundred eighty-eight".