21221001121 has 4 divisors (see below), whose sum is σ = 21348073152. Its totient is φ = 21093929092.

The previous prime is 21221001103. The next prime is 21221001167. The reversal of 21221001121 is 12110012212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21221001121 - 2³¹ = 19073517473 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21221001101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 63535765 + ... + 63536098.

It is an arithmetic number, because the mean of its divisors is an integer number (5337018288).

Almost surely, 2^21221001121 is an apocalyptic number.

It is an amenable number.

21221001121 is a deficient number, since it is larger than the sum of its proper divisors (127072031).

21221001121 is a wasteful number, since it uses less digits than its factorization.

21221001121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127072030.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21221001121 its reverse (12110012212), we get a palindrome (33331013333).

The spelling of 21221001121 in words is "twenty-one billion, two hundred twenty-one million, one thousand, one hundred twenty-one".