100121001021 has 40 divisors (see below), whose sum is σ = 152336115360. Its totient is φ = 65513497248.

The previous prime is 100121000971. The next prime is 100121001031. The reversal of 100121001021 is 120100121001.

It is a happy number.

It is not a de Polignac number, because 100121001021 - 2¹¹ = 100120998973 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 100121000994 and 100121001012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (100121001031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 3104646 + ... + 3136728.

It is an arithmetic number, because the mean of its divisors is an integer number (3808402884).

Almost surely, 2^100121001021 is an apocalyptic number.

It is an amenable number.

100121001021 is a deficient number, since it is larger than the sum of its proper divisors (52215114339).

100121001021 is an equidigital number, since it uses as much as digits as its factorization.

100121001021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32807 (or 32798 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 100121001021 its reverse (120100121001), we get a palindrome (220221122022).

The spelling of 100121001021 in words is "one hundred billion, one hundred twenty-one million, one thousand, twenty-one".