1231818880 has 64 divisors (see below), whose sum is σ = 2955317400. Its totient is φ = 490971136.

The previous prime is 1231818851. The next prime is 1231818881. The reversal of 1231818880 is 888181321.

It can be written as a sum of positive squares in 4 ways, for example, as 1229484096 + 2334784 = 35064^2 + 1528^2 .

It is a tau number, because it is divible by the number of its divisors (64).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is not an unprimeable number, because it can be changed into a prime (1231818881) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 184236 + ... + 190804.

Almost surely, 2^1231818880 is an apocalyptic number.

1231818880 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 1231818880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1477658700).

1231818880 is an abundant number, since it is smaller than the sum of its proper divisors (1723498520).

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

1231818880 is an equidigital number, since it uses as much as digits as its factorization.

1231818880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6881 (or 6869 counting only the distinct ones).

The product of its (nonzero) digits is 24576, while the sum is 40.

The square root of 1231818880 is about 35097.2773872846. The cubic root of 1231818880 is about 1071.9691459153.

The spelling of 1231818880 in words is "one billion, two hundred thirty-one million, eight hundred eighteen thousand, eight hundred eighty".