210099109021 has 4 divisors (see below), whose sum is σ = 210113794044. Its totient is φ = 210084424000.

The previous prime is 210099109009. The next prime is 210099109037. The reversal of 210099109021 is 120901990012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8242097796 + 201857011225 = 90786^2 + 449285^2 .

It is a cyclic number.

It is not a de Polignac number, because 210099109021 - 2⁹ = 210099108509 is a prime.

It is a super-2 number, since 2×210099109021² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210099109621) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7321030 + ... + 7349671.

It is an arithmetic number, because the mean of its divisors is an integer number (52528448511).

Almost surely, 2^210099109021 is an apocalyptic number.

It is an amenable number.

210099109021 is a deficient number, since it is larger than the sum of its proper divisors (14685023).

210099109021 is a wasteful number, since it uses less digits than its factorization.

210099109021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14685022.

The product of its (nonzero) digits is 2916, while the sum is 34.

The spelling of 210099109021 in words is "two hundred ten billion, ninety-nine million, one hundred nine thousand, twenty-one".