1820231440 has 40 divisors (see below), whose sum is σ = 4239739800. Its totient is φ = 726767616.

The previous prime is 1820231423. The next prime is 1820231447. The reversal of 1820231440 is 441320281.

1820231440 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 52533504 + 1767697936 = 7248^2 + 42044^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (1820231447) 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, 24136 + ... + 64984.

It is an arithmetic number, because the mean of its divisors is an integer number (105993495).

Almost surely, 2^1820231440 is an apocalyptic number.

1820231440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1820231440 is an abundant number, since it is smaller than the sum of its proper divisors (2419508360).

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

1820231440 is a wasteful number, since it uses less digits than its factorization.

1820231440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41419 (or 41413 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 25.

The square root of 1820231440 is about 42664.1704478125. The cubic root of 1820231440 is about 1220.9809006379.

The spelling of 1820231440 in words is "one billion, eight hundred twenty million, two hundred thirty-one thousand, four hundred forty".