1640318840 has 16 divisors (see below), whose sum is σ = 3690717480. Its totient is φ = 656127520.

The previous prime is 1640318839. The next prime is 1640318843. The reversal of 1640318840 is 488130461.

It is a self number, because there is not a number n which added to its sum of digits gives 1640318840.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1640318843) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20503946 + ... + 20504025.

Almost surely, 2^1640318840 is an apocalyptic number.

1640318840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1640318840 is an abundant number, since it is smaller than the sum of its proper divisors (2050398640).

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

1640318840 is a wasteful number, since it uses less digits than its factorization.

1640318840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41007982 (or 41007978 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 35.

The square root of 1640318840 is about 40500.8498676262. The cubic root of 1640318840 is about 1179.3501257309.

The spelling of 1640318840 in words is "one billion, six hundred forty million, three hundred eighteen thousand, eight hundred forty".