1801211780 has 96 divisors (see below), whose sum is σ = 4083851520. Its totient is φ = 665280000.

The previous prime is 1801211773. The next prime is 1801211791. The reversal of 1801211780 is 871121081.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2724650 + ... + 2725310.

It is an arithmetic number, because the mean of its divisors is an integer number (42540120).

Almost surely, 2^1801211780 is an apocalyptic number.

1801211780 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 1801211780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2041925760).

1801211780 is an abundant number, since it is smaller than the sum of its proper divisors (2282639740).

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

1801211780 is a wasteful number, since it uses less digits than its factorization.

1801211780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 861 (or 859 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 29.

The square root of 1801211780 is about 42440.6854327307. The cubic root of 1801211780 is about 1216.7133116122.

It can be divided in two parts, 18012 and 11780, that added together give a palindrome (29792).

The spelling of 1801211780 in words is "one billion, eight hundred one million, two hundred eleven thousand, seven hundred eighty".