21212320231 has 8 divisors (see below), whose sum is σ = 22489631424. Its totient is φ = 19938289920.

The previous prime is 21212320169. The next prime is 21212320243. The reversal of 21212320231 is 13202321212.

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

It is a cyclic number.

It is not a de Polignac number, because 21212320231 - 2¹³ = 21212312039 is a prime.

It is a super-2 number, since 2×21212320231² (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 = 21212320199 and 21212320208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212330231) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 806895 + ... + 832768.

It is an arithmetic number, because the mean of its divisors is an integer number (2811203928).

Almost surely, 2^21212320231 is an apocalyptic number.

21212320231 is a deficient number, since it is larger than the sum of its proper divisors (1277311193).

21212320231 is a wasteful number, since it uses less digits than its factorization.

21212320231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1640441.

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

Adding to 21212320231 its reverse (13202321212), we get a palindrome (34414641443).

The spelling of 21212320231 in words is "twenty-one billion, two hundred twelve million, three hundred twenty thousand, two hundred thirty-one".