1640047860 has 144 divisors (see below), whose sum is σ = 5441829120. Its totient is φ = 396506880.

The previous prime is 1640047853. The next prime is 1640047861. The reversal of 1640047860 is 687400461.

1640047860 is a `hidden beast` number, since 1 + 640 + 0 + 4 + 7 + 8 + 6 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1640047861) 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 47 ways as a sum of consecutive naturals, for example, 915846 + ... + 917634.

It is an arithmetic number, because the mean of its divisors is an integer number (37790480).

Almost surely, 2^1640047860 is an apocalyptic number.

1640047860 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 1640047860, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2720914560).

1640047860 is an abundant number, since it is smaller than the sum of its proper divisors (3801781260).

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

1640047860 is a wasteful number, since it uses less digits than its factorization.

1640047860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2278 (or 2273 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 36.

The square root of 1640047860 is about 40497.5043675533. The cubic root of 1640047860 is about 1179.2851794353.

The spelling of 1640047860 in words is "one billion, six hundred forty million, forty-seven thousand, eight hundred sixty".