2111100021 has 6 divisors (see below), whose sum is σ = 3049366710. Its totient is φ = 1407400008.

The previous prime is 2111099983. The next prime is 2111100023. The reversal of 2111100021 is 1200011112.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 2109564900 + 1535121 = 45930^2 + 1239^2 .

It is not a de Polignac number, because 2111100021 - 2¹⁷ = 2110968949 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9), and also a Moran number because the ratio is a prime number: 234566669 = 2111100021 / (2 + 1 + 1 + 1 + 1 + 0 + 0 + 0 + 2 + 1).

It is a junction number, because it is equal to n+sod(n) for n = 2111099976 and 2111100012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2111100023) 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 5 ways as a sum of consecutive naturals, for example, 117283326 + ... + 117283343.

It is an arithmetic number, because the mean of its divisors is an integer number (508227785).

Almost surely, 2^2111100021 is an apocalyptic number.

It is an amenable number.

2111100021 is a deficient number, since it is larger than the sum of its proper divisors (938266689).

2111100021 is a wasteful number, since it uses less digits than its factorization.

2111100021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 234566675 (or 234566672 counting only the distinct ones).

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

The square root of 2111100021 is about 45946.7084892922. The cubic root of 2111100021 is about 1282.8314640898.

Adding to 2111100021 its reverse (1200011112), we get a palindrome (3311111133).

The spelling of 2111100021 in words is "two billion, one hundred eleven million, one hundred thousand, twenty-one".