100121211221221 has 8 divisors (see below), whose sum is σ = 106011010113624. Its totient is φ = 94231447426560.

The previous prime is 100121211221191. The next prime is 100121211221233. The reversal of 100121211221221 is 122122112121001.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 29796466800996 + 70324744420225 = 5458614^2 + 8385985^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 100121211221221 - 2⁵ = 100121211221189 is a prime.

It is a super-4 number, since 4×100121211221221⁴ (a number of 57 digits) contains 4444 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (100121211231221) 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, 2784510 + ... + 14422063.

It is an arithmetic number, because the mean of its divisors is an integer number (13251376264203).

Almost surely, 2^{100121211221221} is an apocalyptic number.

It is an amenable number.

100121211221221 is a deficient number, since it is larger than the sum of its proper divisors (5889798892403).

100121211221221 is a wasteful number, since it uses less digits than its factorization.

100121211221221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17548871.

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 100121211221221 its reverse (122122112121001), we get a palindrome (222243323342222).

The spelling of 100121211221221 in words is "one hundred trillion, one hundred twenty-one billion, two hundred eleven million, two hundred twenty-one thousand, two hundred twenty-one".