1664231640 has 64 divisors (see below), whose sum is σ = 4999246560. Its totient is φ = 443212800.

The previous prime is 1664231599. The next prime is 1664231663. The reversal of 1664231640 is 461324661.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 86940 + ... + 104340.

Almost surely, 2^1664231640 is an apocalyptic number.

1664231640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1664231640 is an abundant number, since it is smaller than the sum of its proper divisors (3335014920).

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

1664231640 is a wasteful number, since it uses less digits than its factorization.

1664231640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18212 (or 18208 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 33.

The square root of 1664231640 is about 40794.9952812842. The cubic root of 1664231640 is about 1185.0534113973.

The spelling of 1664231640 in words is "one billion, six hundred sixty-four million, two hundred thirty-one thousand, six hundred forty".