1211203222400 has 192 divisors, whose sum is σ = 3070577220480. Its totient is φ = 471831951360.

The previous prime is 1211203222393. The next prime is 1211203222403. The reversal of 1211203222400 is 42223021121.

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 (1211203222403) 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, 47734517 + ... + 47759883.

It is an arithmetic number, because the mean of its divisors is an integer number (15992589690).

Almost surely, 2^{1211203222400} is an apocalyptic number.

1211203222400 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 1211203222400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1535288610240).

1211203222400 is an abundant number, since it is smaller than the sum of its proper divisors (1859373998080).

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

1211203222400 is a wasteful number, since it uses less digits than its factorization.

1211203222400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25781 (or 25764 counting only the distinct ones).

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

Adding to 1211203222400 its reverse (42223021121), we get a palindrome (1253426243521).

The spelling of 1211203222400 in words is "one trillion, two hundred eleven billion, two hundred three million, two hundred twenty-two thousand, four hundred".