213021112421 has 4 divisors (see below), whose sum is σ = 229407351852. Its totient is φ = 196634872992.

The previous prime is 213021112393. The next prime is 213021112427. The reversal of 213021112421 is 124211120312.

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 87340936225 + 125680176196 = 295535^2 + 354514^2 .

It is a cyclic number.

It is not a de Polignac number, because 213021112421 - 2³⁴ = 195841243237 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 213021112393 and 213021112402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213021112427) 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, 8193119696 + ... + 8193119721.

It is an arithmetic number, because the mean of its divisors is an integer number (57351837963).

Almost surely, 2^213021112421 is an apocalyptic number.

It is an amenable number.

213021112421 is a deficient number, since it is larger than the sum of its proper divisors (16386239431).

213021112421 is a wasteful number, since it uses less digits than its factorization.

213021112421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16386239430.

The product of its (nonzero) digits is 192, while the sum is 20.

Adding to 213021112421 its reverse (124211120312), we get a palindrome (337232232733).

The spelling of 213021112421 in words is "two hundred thirteen billion, twenty-one million, one hundred twelve thousand, four hundred twenty-one".