1243321040 has 40 divisors (see below), whose sum is σ = 3113087208. Its totient is φ = 459072000.

The previous prime is 1243321021. The next prime is 1243321043. The reversal of 1243321040 is 401233421.

It can be written as a sum of positive squares in 4 ways, for example, as 130965136 + 1112355904 = 11444^2 + 33352^2 .

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

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1243321043) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 596711 + ... + 598790.

Almost surely, 2^1243321040 is an apocalyptic number.

1243321040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1243321040 is an abundant number, since it is smaller than the sum of its proper divisors (1869766168).

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

1243321040 is a wasteful number, since it uses less digits than its factorization.

1243321040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1195527 (or 1195521 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

The square root of 1243321040 is about 35260.7577910629. The cubic root of 1243321040 is about 1075.2953333143.

Adding to 1243321040 its reverse (401233421), we get a palindrome (1644554461).

The spelling of 1243321040 in words is "one billion, two hundred forty-three million, three hundred twenty-one thousand, forty".