1640423388 has 24 divisors (see below), whose sum is σ = 3994075008. Its totient is φ = 523033456.

The previous prime is 1640423363. The next prime is 1640423399. The reversal of 1640423388 is 8833240461.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 2971506 + ... + 2972057.

It is an arithmetic number, because the mean of its divisors is an integer number (166419792).

Almost surely, 2^1640423388 is an apocalyptic number.

It is an amenable number.

1640423388 is an abundant number, since it is smaller than the sum of its proper divisors (2353651620).

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

1640423388 is a wasteful number, since it uses less digits than its factorization.

1640423388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5943593 (or 5943591 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 39.

The square root of 1640423388 is about 40502.1405360260. The cubic root of 1640423388 is about 1179.3751810381.

The spelling of 1640423388 in words is "one billion, six hundred forty million, four hundred twenty-three thousand, three hundred eighty-eight".