221501515225 has 12 divisors (see below), whose sum is σ = 275861282860. Its totient is φ = 176427403200.

The previous prime is 221501515223. The next prime is 221501515231. The reversal of 221501515225 is 522515105122.

221501515225 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 6 ways, for example, as 71978256 + 221429536969 = 8484^2 + 470563^2 .

It is not a de Polignac number, because 221501515225 - 2¹ = 221501515223 is a prime.

It is not an unprimeable number, because it can be changed into a prime (221501515223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19339386 + ... + 19350835.

Almost surely, 2^221501515225 is an apocalyptic number.

221501515225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

221501515225 is a deficient number, since it is larger than the sum of its proper divisors (54359767635).

221501515225 is a wasteful number, since it uses less digits than its factorization.

221501515225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38690460 (or 38690455 counting only the distinct ones).

The product of its (nonzero) digits is 10000, while the sum is 31.

The spelling of 221501515225 in words is "two hundred twenty-one billion, five hundred one million, five hundred fifteen thousand, two hundred twenty-five".