1525532221 has 2 divisors, whose sum is σ = 1525532222. Its totient is φ = 1525532220.

The previous prime is 1525532191. The next prime is 1525532257. The reversal of 1525532221 is 1222355251.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 876811321 + 648720900 = 29611^2 + 25470^2 .

It is a cyclic number.

It is not a de Polignac number, because 1525532221 - 2⁷ = 1525532093 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1525532221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1525532521) 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 as a sum of consecutive naturals, namely, 762766110 + 762766111.

It is an arithmetic number, because the mean of its divisors is an integer number (762766111).

Almost surely, 2^1525532221 is an apocalyptic number.

It is an amenable number.

1525532221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1525532221 is an equidigital number, since it uses as much as digits as its factorization.

1525532221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6000, while the sum is 28.

The square root of 1525532221 is about 39058.0621767133. The cubic root of 1525532221 is about 1151.1726465766.

Adding to 1525532221 its reverse (1222355251), we get a palindrome (2747887472).

The spelling of 1525532221 in words is "one billion, five hundred twenty-five million, five hundred thirty-two thousand, two hundred twenty-one".