1321423440 has 80 divisors (see below), whose sum is σ = 4196356416. Its totient is φ = 343782400.

The previous prime is 1321423429. The next prime is 1321423487. The reversal of 1321423440 is 443241231.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 1321423440.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 57306 + ... + 76985.

Almost surely, 2^1321423440 is an apocalyptic number.

1321423440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1321423440 is an abundant number, since it is smaller than the sum of its proper divisors (2874932976).

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

1321423440 is a wasteful number, since it uses less digits than its factorization.

1321423440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134348 (or 134342 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 24.

The square root of 1321423440 is about 36351.3884191512. The cubic root of 1321423440 is about 1097.3554765649.

Adding to 1321423440 its reverse (443241231), we get a palindrome (1764664671).

The spelling of 1321423440 in words is "one billion, three hundred twenty-one million, four hundred twenty-three thousand, four hundred forty".