1681778208 has 96 divisors (see below), whose sum is σ = 4982160960. Its totient is φ = 492047360.

The previous prime is 1681778201. The next prime is 1681778257. The reversal of 1681778208 is 8028771861.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is not an unprimeable number, because it can be changed into a prime (1681778201) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3166 + ... + 58082.

It is an arithmetic number, because the mean of its divisors is an integer number (51897510).

Almost surely, 2^1681778208 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1681778208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2491080480).

1681778208 is an abundant number, since it is smaller than the sum of its proper divisors (3300382752).

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

1681778208 is a wasteful number, since it uses less digits than its factorization.

1681778208 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54970 (or 54962 counting only the distinct ones).

The product of its (nonzero) digits is 301056, while the sum is 48.

The square root of 1681778208 is about 41009.4892433446. The cubic root of 1681778208 is about 1189.2036684347.

The spelling of 1681778208 in words is "one billion, six hundred eighty-one million, seven hundred seventy-eight thousand, two hundred eight".