1664431636 has 12 divisors (see below), whose sum is σ = 3328863328. Its totient is φ = 713327832.

The previous prime is 1664431603. The next prime is 1664431661. The reversal of 1664431636 is 6361344661.

1664431636 is an admirable number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29721966 + ... + 29722021.

Almost surely, 2^1664431636 is an apocalyptic number.

It is an amenable number.

1664431636 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

1664431636 is a wasteful number, since it uses less digits than its factorization.

1664431636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59443998 (or 59443996 counting only the distinct ones).

The product of its digits is 186624, while the sum is 40.

The square root of 1664431636 is about 40797.4464396977. The cubic root of 1664431636 is about 1185.1008800395.

The spelling of 1664431636 in words is "one billion, six hundred sixty-four million, four hundred thirty-one thousand, six hundred thirty-six".