155221 has 8 divisors (see below), whose sum is σ = 172224.
Its totient is φ = 138720.
The previous prime is 155219. The next prime is 155231. The reversal of 155221 is 122551.
Adding to 155221 its reverse (122551), we get a palindrome (277772).
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 155221 - 21 = 155219 is a prime.
It is a Duffinian number.
It is a junction number, because it is equal to n+sod(n) for n = 155195 and 155204.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (155201) 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, 1065 + ... + 1201.
It is an arithmetic number, because the mean of its divisors is an integer number (21528).
2155221 is an apocalyptic number.
155221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.
It is an amenable number.
155221 is a deficient number, since it is larger than the sum of its proper divisors (17003).
155221 is a wasteful number, since it uses less digits than its factorization.
155221 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 251.
The product of its digits is 100, while the sum is 16.
The square root of 155221 is about 393.9809640071.
The cubic root of 155221 is about 53.7423713709.
The spelling of 155221 in words is "one hundred fifty-five thousand, two hundred twenty-one".