221520151 has 2 divisors, whose sum is σ = 221520152. Its totient is φ = 221520150.

The previous prime is 221520137. The next prime is 221520163. The reversal of 221520151 is 151025122.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 221520151 - 2⁵ = 221520119 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221520121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110760075 + 110760076.

It is an arithmetic number, because the mean of its divisors is an integer number (110760076).

Almost surely, 2^221520151 is an apocalyptic number.

221520151 is a deficient number, since it is larger than the sum of its proper divisors (1).

221520151 is an equidigital number, since it uses as much as digits as its factorization.

221520151 is an evil number, because the sum of its binary digits is even.

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

The square root of 221520151 is about 14883.5530368256. The cubic root of 221520151 is about 605.0683173086.

Adding to 221520151 its reverse (151025122), we get a palindrome (372545273).

It can be divided in two parts, 2215 and 20151, that added together give a triangular number (22366 = T₂₁₁).

The spelling of 221520151 in words is "two hundred twenty-one million, five hundred twenty thousand, one hundred fifty-one".