1649921856 has 112 divisors (see below), whose sum is σ = 4829787648. Its totient is φ = 492889600.

The previous prime is 1649921851. The next prime is 1649921857. The reversal of 1649921856 is 6581299461.

It is a junction number, because it is equal to n+sod(n) for n = 1649921799 and 1649921808.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1649921851) 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, 144451 + ... + 155453.

It is an arithmetic number, because the mean of its divisors is an integer number (43123104).

Almost surely, 2^1649921856 is an apocalyptic number.

1649921856 is a gapful number since it is divisible by the number (16) 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 1649921856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2414893824).

1649921856 is an abundant number, since it is smaller than the sum of its proper divisors (3179865792).

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

1649921856 is a wasteful number, since it uses less digits than its factorization.

1649921856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11100 (or 11090 counting only the distinct ones).

The product of its digits is 933120, while the sum is 51.

The square root of 1649921856 is about 40619.2301256437. The cubic root of 1649921856 is about 1181.6470956097.

The spelling of 1649921856 in words is "one billion, six hundred forty-nine million, nine hundred twenty-one thousand, eight hundred fifty-six".