1213041440 has 144 divisors (see below), whose sum is σ = 3138562728. Its totient is φ = 442810368.

The previous prime is 1213041433. The next prime is 1213041449. The reversal of 1213041440 is 441403121.

It can be written as a sum of positive squares in 12 ways, for example, as 111598096 + 1101443344 = 10564^2 + 33188^2 .

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 (1213041449) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3055322 + ... + 3055718.

Almost surely, 2^1213041440 is an apocalyptic number.

1213041440 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 1213041440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1569281364).

1213041440 is an abundant number, since it is smaller than the sum of its proper divisors (1925521288).

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

1213041440 is a wasteful number, since it uses less digits than its factorization.

1213041440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 551 (or 530 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 1213041440 is about 34828.7444505253. The cubic root of 1213041440 is about 1066.4943176399.

Adding to 1213041440 its reverse (441403121), we get a palindrome (1654444561).

The spelling of 1213041440 in words is "one billion, two hundred thirteen million, forty-one thousand, four hundred forty".