213100210021 has 2 divisors, whose sum is σ = 213100210022. Its totient is φ = 213100210020.

The previous prime is 213100209997. The next prime is 213100210031. The reversal of 213100210021 is 120012001312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 212691604225 + 408605796 = 461185^2 + 20214^2 .

It is a cyclic number.

It is not a de Polignac number, because 213100210021 - 2²⁵ = 213066655589 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 213100209983 and 213100210010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (213100210031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106550105010 + 106550105011.

It is an arithmetic number, because the mean of its divisors is an integer number (106550105011).

Almost surely, 2^213100210021 is an apocalyptic number.

It is an amenable number.

213100210021 is a deficient number, since it is larger than the sum of its proper divisors (1).

213100210021 is an equidigital number, since it uses as much as digits as its factorization.

213100210021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24, while the sum is 13.

Adding to 213100210021 its reverse (120012001312), we get a palindrome (333112211333).

The spelling of 213100210021 in words is "two hundred thirteen billion, one hundred million, two hundred ten thousand, twenty-one".