12921231 has 4 divisors (see below), whose sum is σ = 17228312. Its totient is φ = 8614152.

The previous prime is 12921217. The next prime is 12921263. The reversal of 12921231 is 13212921.

12921231 is digitally balanced in base 2, base 3 and base 4, because in such bases it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 12921231 - 2¹³ = 12913039 is a prime.

It is a super-2 number, since 2×12921231² = 333916421110722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12921198 and 12921207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12921281) 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, 2153536 + ... + 2153541.

It is an arithmetic number, because the mean of its divisors is an integer number (4307078).

Almost surely, 2^12921231 is an apocalyptic number.

12921231 is a deficient number, since it is larger than the sum of its proper divisors (4307081).

12921231 is an equidigital number, since it uses as much as digits as its factorization.

12921231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4307080.

The product of its digits is 216, while the sum is 21.

The square root of 12921231 is about 3594.6113837243. The cubic root of 12921231 is about 234.6576030723.

The spelling of 12921231 in words is "twelve million, nine hundred twenty-one thousand, two hundred thirty-one".