4155221 has 4 divisors (see below), whose sum is σ = 4748832. Its totient is φ = 3561612.

The previous prime is 4155197. The next prime is 4155247. The reversal of 4155221 is 1225514.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 4155221 - 2¹⁰ = 4154197 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 4155193 and 4155202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4155251) 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, 296795 + ... + 296808.

It is an arithmetic number, because the mean of its divisors is an integer number (1187208).

Almost surely, 2^4155221 is an apocalyptic number.

It is an amenable number.

4155221 is a deficient number, since it is larger than the sum of its proper divisors (593611).

4155221 is an equidigital number, since it uses as much as digits as its factorization.

4155221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 593610.

The product of its digits is 400, while the sum is 20.

The square root of 4155221 is about 2038.4359200132. The cubic root of 4155221 is about 160.7674200514.

The spelling of 4155221 in words is "four million, one hundred fifty-five thousand, two hundred twenty-one".