210130021 has 4 divisors (see below), whose sum is σ = 212661792. Its totient is φ = 207598252.

The previous prime is 210130007. The next prime is 210130049. The reversal of 210130021 is 120031012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 210130021 - 2¹³ = 210121829 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210130051) 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, 1265761 + ... + 1265926.

It is an arithmetic number, because the mean of its divisors is an integer number (53165448).

Almost surely, 2^210130021 is an apocalyptic number.

It is an amenable number.

210130021 is a deficient number, since it is larger than the sum of its proper divisors (2531771).

210130021 is an equidigital number, since it uses as much as digits as its factorization.

210130021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2531770.

The product of its (nonzero) digits is 12, while the sum is 10.

The square root of 210130021 is about 14495.8622027115. The cubic root of 210130021 is about 594.5148421385.

Adding to 210130021 its reverse (120031012), we get a palindrome (330161033).

Subtracting from 210130021 its reverse (120031012), we obtain a palindrome (90099009).

The spelling of 210130021 in words is "two hundred ten million, one hundred thirty thousand, twenty-one".