1664400012 has 36 divisors (see below), whose sum is σ = 4268754168. Its totient is φ = 504363200.

The previous prime is 1664399999. The next prime is 1664400077. The reversal of 1664400012 is 2100044661.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 571689 + ... + 574592.

Almost surely, 2^1664400012 is an apocalyptic number.

1664400012 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1664400012 is an abundant number, since it is smaller than the sum of its proper divisors (2604354156).

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

1664400012 is a wasteful number, since it uses less digits than its factorization.

1664400012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1146310 (or 1146297 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 1664400012 is about 40797.0588645799. The cubic root of 1664400012 is about 1185.0933744008.

Adding to 1664400012 its reverse (2100044661), we get a palindrome (3764444673).

The spelling of 1664400012 in words is "one billion, six hundred sixty-four million, four hundred thousand, twelve".