1681766550 has 336 divisors, whose sum is σ = 5098713840. Its totient is φ = 411505920.

The previous prime is 1681766543. The next prime is 1681766561. The reversal of 1681766550 is 556671861.

1681766550 is a `hidden beast` number, since 16 + 81 + 7 + 6 + 6 + 550 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1681766496 and 1681766505.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 167 ways as a sum of consecutive naturals, for example, 39110829 + ... + 39110871.

Almost surely, 2^1681766550 is an apocalyptic number.

1681766550 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1681766550, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2549356920).

1681766550 is an abundant number, since it is smaller than the sum of its proper divisors (3416947290).

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

1681766550 is a wasteful number, since it uses less digits than its factorization.

1681766550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139 (or 119 counting only the distinct ones).

The product of its (nonzero) digits is 302400, while the sum is 45.

The square root of 1681766550 is about 41009.3471052637. The cubic root of 1681766550 is about 1189.2009205954.

The spelling of 1681766550 in words is "one billion, six hundred eighty-one million, seven hundred sixty-six thousand, five hundred fifty".