1811688660 has 96 divisors (see below), whose sum is σ = 5643751680. Its totient is φ = 482484096.

The previous prime is 1811688653. The next prime is 1811688661. The reversal of 1811688660 is 668861181.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1811688661) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 529114 + ... + 532526.

It is an arithmetic number, because the mean of its divisors is an integer number (58789080).

Almost surely, 2^1811688660 is an apocalyptic number.

1811688660 is a gapful number since it is divisible by the number (10) 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 1811688660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2821875840).

1811688660 is an abundant number, since it is smaller than the sum of its proper divisors (3832063020).

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

1811688660 is a wasteful number, since it uses less digits than its factorization.

1811688660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4414 (or 4406 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 45.

The square root of 1811688660 is about 42563.9361431717. The cubic root of 1811688660 is about 1219.0677864798.

The spelling of 1811688660 in words is "one billion, eight hundred eleven million, six hundred eighty-eight thousand, six hundred sixty".