12155921 has 8 divisors (see below), whose sum is σ = 12455424. Its totient is φ = 11859120.

The previous prime is 12155917. The next prime is 12155929. The reversal of 12155921 is 12955121.

12155921 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 12155921 - 2² = 12155917 is a prime.

It is not an unprimeable number, because it can be changed into a prime (12155929) 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, 10640 + ... + 11726.

It is an arithmetic number, because the mean of its divisors is an integer number (1556928).

Almost surely, 2^12155921 is an apocalyptic number.

It is an amenable number.

12155921 is a deficient number, since it is larger than the sum of its proper divisors (299503).

12155921 is a wasteful number, since it uses less digits than its factorization.

12155921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1351.

The product of its digits is 900, while the sum is 26.

The square root of 12155921 is about 3486.5342390403. The cubic root of 12155921 is about 229.9301678358.

The spelling of 12155921 in words is "twelve million, one hundred fifty-five thousand, nine hundred twenty-one".