21121000001100 has 144 divisors (see below), whose sum is σ = 67979156694400. Its totient is φ = 5625709277760.

The previous prime is 21121000001089. The next prime is 21121000001119. The reversal of 21121000001100 is 110000012112.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2234014 + ... + 6872613.

Almost surely, 2^{21121000001100} is an apocalyptic number.

21121000001100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21121000001100 is an abundant number, since it is smaller than the sum of its proper divisors (46858156693300).

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

21121000001100 is a wasteful number, since it uses less digits than its factorization.

21121000001100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9107509 (or 9107496 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 21121000001100 its reverse (110000012112), we get a palindrome (21231000013212).

The spelling of 21121000001100 in words is "twenty-one trillion, one hundred twenty-one billion, one thousand, one hundred".