21213033231 has 8 divisors (see below), whose sum is σ = 30459740080. Its totient is φ = 13054174272.

The previous prime is 21213033209. The next prime is 21213033241. The reversal of 21213033231 is 13233031212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21213033231 - 2⁶ = 21213033167 is a prime.

It is a super-2 number, since 2×21213033231² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21213033198 and 21213033207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21213033241) 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 7 ways as a sum of consecutive naturals, for example, 271961926 + ... + 271962003.

It is an arithmetic number, because the mean of its divisors is an integer number (3807467510).

Almost surely, 2^21213033231 is an apocalyptic number.

21213033231 is a deficient number, since it is larger than the sum of its proper divisors (9246706849).

21213033231 is a wasteful number, since it uses less digits than its factorization.

21213033231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 543923945.

The product of its (nonzero) digits is 648, while the sum is 21.

Adding to 21213033231 its reverse (13233031212), we get a palindrome (34446064443).

The spelling of 21213033231 in words is "twenty-one billion, two hundred thirteen million, thirty-three thousand, two hundred thirty-one".