213423234021 has 20 divisors (see below), whose sum is σ = 320486648064. Its totient is φ = 141537213000.

The previous prime is 213423234007. The next prime is 213423234091. The reversal of 213423234021 is 120432324312.

213423234021 is a `hidden beast` number, since 2 + 1 + 3 + 423 + 234 + 0 + 2 + 1 = 666.

It is not a de Polignac number, because 213423234021 - 2⁶ = 213423233957 is a prime.

It is a super-3 number, since 3×213423234021³ (a number of 35 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213423234091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 6882055 + ... + 6912996.

Almost surely, 2^213423234021 is an apocalyptic number.

It is an amenable number.

213423234021 is a deficient number, since it is larger than the sum of its proper divisors (107063414043).

213423234021 is a wasteful number, since it uses less digits than its factorization.

213423234021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13795254 (or 13795245 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 27.

Adding to 213423234021 its reverse (120432324312), we get a palindrome (333855558333).

The spelling of 213423234021 in words is "two hundred thirteen billion, four hundred twenty-three million, two hundred thirty-four thousand, twenty-one".