1211121226560 has 224 divisors, whose sum is σ = 4496841879552. Its totient is φ = 270389790720.

The previous prime is 1211121226543. The next prime is 1211121226561. The reversal of 1211121226560 is 656221211121.

It is a tau number, because it is divible by the number of its divisors (224).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211121226561) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1806696 + ... + 2384615.

Almost surely, 2^{1211121226560} is an apocalyptic number.

1211121226560 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1211121226560 is an abundant number, since it is smaller than the sum of its proper divisors (3285720652992).

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

1211121226560 is a wasteful number, since it uses less digits than its factorization.

1211121226560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4191381 (or 4191371 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 30.

Adding to 1211121226560 its reverse (656221211121), we get a palindrome (1867342437681).

The spelling of 1211121226560 in words is "one trillion, two hundred eleven billion, one hundred twenty-one million, two hundred twenty-six thousand, five hundred sixty".