1211420204400 has 480 divisors, whose sum is σ = 4524718399488. Its totient is φ = 271339084800.

The previous prime is 1211420204389. The next prime is 1211420204437. The reversal of 1211420204400 is 44020241121.

It is a super-3 number, since 3×1211420204400³ (a number of 37 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 99592719 + ... + 99604881.

Almost surely, 2^{1211420204400} is an apocalyptic number.

1211420204400 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 1211420204400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2262359199744).

1211420204400 is an abundant number, since it is smaller than the sum of its proper divisors (3313298195088).

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

1211420204400 is a wasteful number, since it uses less digits than its factorization.

1211420204400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12429 (or 12418 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 21.

Adding to 1211420204400 its reverse (44020241121), we get a palindrome (1255440445521).

The spelling of 1211420204400 in words is "one trillion, two hundred eleven billion, four hundred twenty million, two hundred four thousand, four hundred".