151221 has 16 divisors (see below), whose sum is σ = 243200.
Its totient is φ = 81648.
The previous prime is 151213. The next prime is 151237. The reversal of 151221 is 122151.
It is not a de Polignac number, because 151221 - 23 = 151213 is a prime.
It is a Curzon number.
151221 is a lucky number.
It is a junction number, because it is equal to n+sod(n) for n = 151197 and 151206.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (151201) by changing a digit.
It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 210 + ... + 588.
It is an arithmetic number, because the mean of its divisors is an integer number (15200).
2151221 is an apocalyptic number.
It is an amenable number.
151221 is a deficient number, since it is larger than the sum of its proper divisors (91979).
151221 is a wasteful number, since it uses less digits than its factorization.
151221 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 408.
The product of its digits is 20, while the sum is 12.
The square root of 151221 is about 388.8714440532.
The cubic root of 151221 is about 53.2767063904.
Adding to 151221 its reverse (122151), we get a palindrome (273372).
The spelling of 151221 in words is "one hundred fifty-one thousand, two hundred twenty-one".