21230423231 has 4 divisors (see below), whose sum is σ = 21232321464. Its totient is φ = 21228525000.

The previous prime is 21230423213. The next prime is 21230423233. The reversal of 21230423231 is 13232403212.

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 21230423231 - 2²² = 21226228927 is a prime.

It is a super-2 number, since 2×21230423231² (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 = 21230423197 and 21230423206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21230423233) 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, 932240 + ... + 954741.

It is an arithmetic number, because the mean of its divisors is an integer number (5308080366).

Almost surely, 2^21230423231 is an apocalyptic number.

21230423231 is a deficient number, since it is larger than the sum of its proper divisors (1898233).

21230423231 is a wasteful number, since it uses less digits than its factorization.

21230423231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1898232.

The product of its (nonzero) digits is 1728, while the sum is 23.

Adding to 21230423231 its reverse (13232403212), we get a palindrome (34462826443).

The spelling of 21230423231 in words is "twenty-one billion, two hundred thirty million, four hundred twenty-three thousand, two hundred thirty-one".