151520221 has 4 divisors (see below), whose sum is σ = 151757244. Its totient is φ = 151283200.

The previous prime is 151520209. The next prime is 151520227. The reversal of 151520221 is 122025151.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 122025151 = 431 ⋅283121.

It can be written as a sum of positive squares in 2 ways, for example, as 143736121 + 7784100 = 11989^2 + 2790^2 .

It is a cyclic number.

It is not a de Polignac number, because 151520221 - 2⁵ = 151520189 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 (151520227) 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, 117550 + ... + 118831.

It is an arithmetic number, because the mean of its divisors is an integer number (37939311).

Almost surely, 2^151520221 is an apocalyptic number.

It is an amenable number.

151520221 is a deficient number, since it is larger than the sum of its proper divisors (237023).

151520221 is an equidigital number, since it uses as much as digits as its factorization.

151520221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 237022.

The product of its (nonzero) digits is 200, while the sum is 19.

The square root of 151520221 is about 12309.3550196588. The cubic root of 151520221 is about 533.1182277946.

Adding to 151520221 its reverse (122025151), we get a palindrome (273545372).

It can be divided in two parts, 1515 and 20221, that added together give a triangular number (21736 = T₂₀₈).

The spelling of 151520221 in words is "one hundred fifty-one million, five hundred twenty thousand, two hundred twenty-one".