1321133042400 has 144 divisors (see below), whose sum is σ = 4302530120448. Its totient is φ = 352118464000.

The previous prime is 1321133042381. The next prime is 1321133042401. The reversal of 1321133042400 is 42403311231.

It is a happy number.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321133042401) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4491865 + ... + 4776935.

It is an arithmetic number, because the mean of its divisors is an integer number (29878681392).

Almost surely, 2^{1321133042400} is an apocalyptic number.

1321133042400 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 1321133042400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2151265060224).

1321133042400 is an abundant number, since it is smaller than the sum of its proper divisors (2981397078048).

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

1321133042400 is a wasteful number, since it uses less digits than its factorization.

1321133042400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 287025 (or 287012 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 24.

Adding to 1321133042400 its reverse (42403311231), we get a palindrome (1363536353631).

The spelling of 1321133042400 in words is "one trillion, three hundred twenty-one billion, one hundred thirty-three million, forty-two thousand, four hundred".