1321115400 has 384 divisors, whose sum is σ = 5185382400. Its totient is φ = 306028800.

The previous prime is 1321115363. The next prime is 1321115443. The reversal of 1321115400 is 45111231.

1321115400 is a `hidden beast` number, since 13 + 2 + 111 + 540 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1365717 + ... + 1366683.

It is an arithmetic number, because the mean of its divisors is an integer number (13503600).

Almost surely, 2^1321115400 is an apocalyptic number.

1321115400 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 1321115400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2592691200).

1321115400 is an abundant number, since it is smaller than the sum of its proper divisors (3864267000).

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

1321115400 is a wasteful number, since it uses less digits than its factorization.

1321115400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1026 (or 1011 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 18.

The square root of 1321115400 is about 36347.1511951074. The cubic root of 1321115400 is about 1097.2702009345.

Adding to 1321115400 its reverse (45111231), we get a palindrome (1366226631).

The spelling of 1321115400 in words is "one billion, three hundred twenty-one million, one hundred fifteen thousand, four hundred".