1640085040 has 80 divisors (see below), whose sum is σ = 4228184736. Its totient is φ = 586598400.

The previous prime is 1640085037. The next prime is 1640085043. The reversal of 1640085040 is 405800461.

It is an interprime number because it is at equal distance from previous prime (1640085037) and next prime (1640085043).

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (1640085043) by changing a digit.

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, 38404 + ... + 68956.

Almost surely, 2^1640085040 is an apocalyptic number.

1640085040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1640085040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2114092368).

1640085040 is an abundant number, since it is smaller than the sum of its proper divisors (2588099696).

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

1640085040 is a wasteful number, since it uses less digits than its factorization.

1640085040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30638 (or 30632 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 28.

The square root of 1640085040 is about 40497.9634055837. The cubic root of 1640085040 is about 1179.2940908605.

The spelling of 1640085040 in words is "one billion, six hundred forty million, eighty-five thousand, forty".