1640171808 has 384 divisors, whose sum is σ = 5689958400. Its totient is φ = 454118400.

The previous prime is 1640171807. The next prime is 1640171861. The reversal of 1640171808 is 8081710461.

1640171808 is a `hidden beast` number, since 1 + 640 + 1 + 7 + 1 + 8 + 0 + 8 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (1640171801) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 5597710 + ... + 5598002.

It is an arithmetic number, because the mean of its divisors is an integer number (14817600).

Almost surely, 2^1640171808 is an apocalyptic number.

1640171808 is a gapful number since it is divisible by the number (18) 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 1640171808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2844979200).

1640171808 is an abundant number, since it is smaller than the sum of its proper divisors (4049786592).

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

1640171808 is a wasteful number, since it uses less digits than its factorization.

1640171808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 373 (or 359 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 36.

The square root of 1640171808 is about 40499.0346551618. The cubic root of 1640171808 is about 1179.3148871775.

It can be divided in two parts, 16401 and 71808, that added together give a square (88209 = 297²).

The spelling of 1640171808 in words is "one billion, six hundred forty million, one hundred seventy-one thousand, eight hundred eight".