100001121021 has 28 divisors (see below), whose sum is σ = 156451950048. Its totient is φ = 63768820104.

The previous prime is 100001121019. The next prime is 100001121023. The reversal of 100001121021 is 120121100001.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (100001121019) and next prime (100001121023).

It is not a de Polignac number, because 100001121021 - 2¹ = 100001121019 is a prime.

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

It is a junction number, because it is equal to n+sod(n) for n = 100001120994 and 100001121012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (100001121023) by changing a digit.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 2965315 + ... + 2998848.

Almost surely, 2^100001121021 is an apocalyptic number.

It is an amenable number.

100001121021 is a deficient number, since it is larger than the sum of its proper divisors (56450829027).

100001121021 is an frugal number, since it uses more digits than its factorization.

100001121021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5964204 (or 5964189 counting only the distinct ones).

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

Adding to 100001121021 its reverse (120121100001), we get a palindrome (220122221022).

The spelling of 100001121021 in words is "one hundred billion, one million, one hundred twenty-one thousand, twenty-one".