21331100121 has 8 divisors (see below), whose sum is σ = 28525864224. Its totient is φ = 14178534720.

The previous prime is 21331100069. The next prime is 21331100159. The reversal of 21331100121 is 12100113312.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21331100121 - 2⁶ = 21331100057 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21331100121.

It is not an unprimeable number, because it can be changed into a prime (21331100321) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10548495 + ... + 10550516.

It is an arithmetic number, because the mean of its divisors is an integer number (3565733028).

Almost surely, 2^21331100121 is an apocalyptic number.

It is an amenable number.

21331100121 is a deficient number, since it is larger than the sum of its proper divisors (7194764103).

21331100121 is a wasteful number, since it uses less digits than its factorization.

21331100121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21099351.

The product of its (nonzero) digits is 36, while the sum is 15.

Adding to 21331100121 its reverse (12100113312), we get a palindrome (33431213433).

The spelling of 21331100121 in words is "twenty-one billion, three hundred thirty-one million, one hundred thousand, one hundred twenty-one".