151532221 has 6 divisors (see below), whose sum is σ = 156938522. Its totient is φ = 146306160.

The previous prime is 151532197. The next prime is 151532231. The reversal of 151532221 is 122235151.

It can be written as a sum of positive squares in 3 ways, for example, as 11464996 + 140067225 = 3386^2 + 11835^2 .

It is not a de Polignac number, because 151532221 - 2⁷ = 151532093 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 151532192 and 151532201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (151532231) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 89250 + ... + 90931.

Almost surely, 2^151532221 is an apocalyptic number.

It is an amenable number.

151532221 is a deficient number, since it is larger than the sum of its proper divisors (5406301).

151532221 is an equidigital number, since it uses as much as digits as its factorization.

151532221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 180239 (or 180210 counting only the distinct ones).

The product of its digits is 600, while the sum is 22.

The square root of 151532221 is about 12309.8424441583. The cubic root of 151532221 is about 533.1323012734.

Adding to 151532221 its reverse (122235151), we get a palindrome (273767372).

The spelling of 151532221 in words is "one hundred fifty-one million, five hundred thirty-two thousand, two hundred twenty-one".