213243100021 has 16 divisors (see below), whose sum is σ = 244529031168. Its totient is φ = 182163870000.

The previous prime is 213243099991. The next prime is 213243100093. The reversal of 213243100021 is 120001342312.

It is a happy number.

It is not a de Polignac number, because 213243100021 - 2¹³ = 213243091829 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 (213243100621) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2443896 + ... + 2529646.

It is an arithmetic number, because the mean of its divisors is an integer number (15283064448).

Almost surely, 2^213243100021 is an apocalyptic number.

It is an amenable number.

213243100021 is a deficient number, since it is larger than the sum of its proper divisors (31285931147).

213243100021 is an equidigital number, since it uses as much as digits as its factorization.

213243100021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86952.

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 213243100021 its reverse (120001342312), we get a palindrome (333244442333).

The spelling of 213243100021 in words is "two hundred thirteen billion, two hundred forty-three million, one hundred thousand, twenty-one".