152521221 has 4 divisors (see below), whose sum is σ = 203361632. Its totient is φ = 101680812.

The previous prime is 152521217. The next prime is 152521241. The reversal of 152521221 is 122125251.

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, and also an emirpimes, since its reverse is a distinct semiprime: 122125251 = 3 ⋅40708417.

It is not a de Polignac number, because 152521221 - 2² = 152521217 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (152521241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25420201 + ... + 25420206.

It is an arithmetic number, because the mean of its divisors is an integer number (50840408).

Almost surely, 2^152521221 is an apocalyptic number.

It is an amenable number.

152521221 is a deficient number, since it is larger than the sum of its proper divisors (50840411).

152521221 is an equidigital number, since it uses as much as digits as its factorization.

152521221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50840410.

The product of its digits is 400, while the sum is 21.

The square root of 152521221 is about 12349.9482185149. The cubic root of 152521221 is about 534.2896456402.

Adding to 152521221 its reverse (122125251), we get a palindrome (274646472).

The spelling of 152521221 in words is "one hundred fifty-two million, five hundred twenty-one thousand, two hundred twenty-one".