1220401321400 has 96 divisors (see below), whose sum is σ = 2873351897280. Its totient is φ = 482007360000.

The previous prime is 1220401321387. The next prime is 1220401321421. The reversal of 1220401321400 is 41231040221.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7331090 + ... + 7495710.

It is an arithmetic number, because the mean of its divisors is an integer number (29930748930).

Almost surely, 2^{1220401321400} is an apocalyptic number.

1220401321400 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 1220401321400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1436675948640).

1220401321400 is an abundant number, since it is smaller than the sum of its proper divisors (1652950575880).

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

1220401321400 is a wasteful number, since it uses less digits than its factorization.

1220401321400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165105 (or 165096 counting only the distinct ones).

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

Adding to 1220401321400 its reverse (41231040221), we get a palindrome (1261632361621).

The spelling of 1220401321400 in words is "one trillion, two hundred twenty billion, four hundred one million, three hundred twenty-one thousand, four hundred".