2121100101 has 12 divisors (see below), whose sum is σ = 3177286112. Its totient is φ = 1414066572.

The previous prime is 2121100099. The next prime is 2121100103. The reversal of 2121100101 is 1010011212.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (2121100099) and next prime (2121100103).

It is not a de Polignac number, because 2121100101 - 2¹ = 2121100099 is a prime.

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

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121100103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4364161 + ... + 4364646.

Almost surely, 2^2121100101 is an apocalyptic number.

It is an amenable number.

2121100101 is a deficient number, since it is larger than the sum of its proper divisors (1056186011).

2121100101 is an frugal number, since it uses more digits than its factorization.

2121100101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8728822 (or 8728810 counting only the distinct ones).

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

The square root of 2121100101 is about 46055.4025169686. The cubic root of 2121100101 is about 1284.8538244096.

Adding to 2121100101 its reverse (1010011212), we get a palindrome (3131111313).

Subtracting from 2121100101 its reverse (1010011212), we obtain a square (1111088889 = 33333²).

The spelling of 2121100101 in words is "two billion, one hundred twenty-one million, one hundred thousand, one hundred one".