21233430331 has 4 divisors (see below), whose sum is σ = 21250596832. Its totient is φ = 21216263832.

The previous prime is 21233430313. The next prime is 21233430347. The reversal of 21233430331 is 13303433212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21233430331 - 2⁷ = 21233430203 is a prime.

It is a super-2 number, since 2×21233430331² (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 = 21233430296 and 21233430305.

It is not an unprimeable number, because it can be changed into a prime (21233430301) 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, 8581395 + ... + 8583868.

It is an arithmetic number, because the mean of its divisors is an integer number (5312649208).

Almost surely, 2^21233430331 is an apocalyptic number.

21233430331 is a deficient number, since it is larger than the sum of its proper divisors (17166501).

21233430331 is a wasteful number, since it uses less digits than its factorization.

21233430331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17166500.

The product of its (nonzero) digits is 3888, while the sum is 25.

Adding to 21233430331 its reverse (13303433212), we get a palindrome (34536863543).

The spelling of 21233430331 in words is "twenty-one billion, two hundred thirty-three million, four hundred thirty thousand, three hundred thirty-one".