121221662221 has 16 divisors (see below), whose sum is σ = 140045899968. Its totient is φ = 103700435200.

The previous prime is 121221662213. The next prime is 121221662227. The reversal of 121221662221 is 122266122121.

It is a happy number.

It is not a de Polignac number, because 121221662221 - 2³ = 121221662213 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 121221662221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121221662227) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1040706 + ... + 1151308.

It is an arithmetic number, because the mean of its divisors is an integer number (8752868748).

Almost surely, 2^121221662221 is an apocalyptic number.

121221662221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

121221662221 is a deficient number, since it is larger than the sum of its proper divisors (18824237747).

121221662221 is a wasteful number, since it uses less digits than its factorization.

121221662221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116492.

The product of its digits is 2304, while the sum is 28.

Adding to 121221662221 its reverse (122266122121), we get a palindrome (243487784342).

The spelling of 121221662221 in words is "one hundred twenty-one billion, two hundred twenty-one million, six hundred sixty-two thousand, two hundred twenty-one".