1221011121100 has 36 divisors (see below), whose sum is σ = 2652031897984. Its totient is φ = 487955090880.

The previous prime is 1221011121079. The next prime is 1221011121101. The reversal of 1221011121100 is 11211101221.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (1221011121101) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5507727 + ... + 5725126.

Almost surely, 2^{1221011121100} is an apocalyptic number.

1221011121100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221011121100 is an abundant number, since it is smaller than the sum of its proper divisors (1431020776884).

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

1221011121100 is a wasteful number, since it uses less digits than its factorization.

1221011121100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11233954 (or 11233947 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 1221011121100 its reverse (11211101221), we get a palindrome (1232222222321).

The spelling of 1221011121100 in words is "one trillion, two hundred twenty-one billion, eleven million, one hundred twenty-one thousand, one hundred".