221210122121121 has 16 divisors (see below), whose sum is σ = 337088120467328. Its totient is φ = 126403522963200.

The previous prime is 221210122121113. The next prime is 221210122121129. The reversal of 221210122121121 is 121121221012122.

It is an interprime number because it is at equal distance from previous prime (221210122121113) and next prime (221210122121129).

It is not a de Polignac number, because 221210122121121 - 2³ = 221210122121113 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221210122121129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 93010450 + ... + 95359131.

It is an arithmetic number, because the mean of its divisors is an integer number (21068007529208).

Almost surely, 2^{221210122121121} is an apocalyptic number.

221210122121121 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

221210122121121 is a deficient number, since it is larger than the sum of its proper divisors (115877998346207).

221210122121121 is a wasteful number, since it uses less digits than its factorization.

221210122121121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 188425512.

The product of its (nonzero) digits is 128, while the sum is 21.

Adding to 221210122121121 its reverse (121121221012122), we get a palindrome (342331343133243).

The spelling of 221210122121121 in words is "two hundred twenty-one trillion, two hundred ten billion, one hundred twenty-two million, one hundred twenty-one thousand, one hundred twenty-one".