210000111021 has 6 divisors (see below), whose sum is σ = 303333493710. Its totient is φ = 140000074008.

The previous prime is 210000111017. The next prime is 210000111023. The reversal of 210000111021 is 120111000012.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 201050004996 + 8950106025 = 448386^2 + 94605^2 .

It is not a de Polignac number, because 210000111021 - 2² = 210000111017 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: 23333345669 = 210000111021 / (2 + 1 + 0 + 0 + 0 + 0 + 1 + 1 + 1 + 0 + 2 + 1).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 210000110994 and 210000111012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210000111023) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11666672826 + ... + 11666672843.

It is an arithmetic number, because the mean of its divisors is an integer number (50555582285).

Almost surely, 2^210000111021 is an apocalyptic number.

It is an amenable number.

210000111021 is a deficient number, since it is larger than the sum of its proper divisors (93333382689).

210000111021 is a wasteful number, since it uses less digits than its factorization.

210000111021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23333345675 (or 23333345672 counting only the distinct ones).

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

Adding to 210000111021 its reverse (120111000012), we get a palindrome (330111111033).

The spelling of 210000111021 in words is "two hundred ten billion, one hundred eleven thousand, twenty-one".