1640798208 has 336 divisors, whose sum is σ = 5657455440. Its totient is φ = 465813504.

The previous prime is 1640798179. The next prime is 1640798209. The reversal of 1640798208 is 8028970461.

It is a tau number, because it is divible by the number of its divisors (336).

It is a super-2 number, since 2×1640798208² = 5384437518752022528, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1640798209) by changing a digit.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 10450866 + ... + 10451022.

It is an arithmetic number, because the mean of its divisors is an integer number (16837665).

Almost surely, 2^1640798208 is an apocalyptic number.

1640798208 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 1640798208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2828727720).

1640798208 is an abundant number, since it is smaller than the sum of its proper divisors (4016657232).

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

1640798208 is an frugal number, since it uses more digits than its factorization.

1640798208 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 204 (or 169 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 45.

The square root of 1640798208 is about 40506.7674345905. The cubic root of 1640798208 is about 1179.4649992612.

The spelling of 1640798208 in words is "one billion, six hundred forty million, seven hundred ninety-eight thousand, two hundred eight".