221321202123121 has 4 divisors (see below), whose sum is σ = 221321413465200. Its totient is φ = 221320990781044.

The previous prime is 221321202123103. The next prime is 221321202123127. The reversal of 221321202123121 is 121321202123122.

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 221321202123121 - 2⁹ = 221321202122609 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221321202123127) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 104092351 + ... + 106197268.

It is an arithmetic number, because the mean of its divisors is an integer number (55330353366300).

Almost surely, 2^{221321202123121} is an apocalyptic number.

It is an amenable number.

221321202123121 is a deficient number, since it is larger than the sum of its proper divisors (211342079).

221321202123121 is a wasteful number, since it uses less digits than its factorization.

221321202123121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 211342078.

The product of its (nonzero) digits is 1152, while the sum is 25.

Adding to 221321202123121 its reverse (121321202123122), we get a palindrome (342642404246243).

Subtracting from 221321202123121 its reverse (121321202123122), we obtain a palindrome (99999999999999).

The spelling of 221321202123121 in words is "two hundred twenty-one trillion, three hundred twenty-one billion, two hundred two million, one hundred twenty-three thousand, one hundred twenty-one".