1221524525 has 12 divisors (see below), whose sum is σ = 1631205492. Its totient is φ = 902048640.

The previous prime is 1221524429. The next prime is 1221524533. The reversal of 1221524525 is 5254251221.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 356341129 + 865183396 = 18877^2 + 29414^2 .

It is not a de Polignac number, because 1221524525 - 2¹² = 1221520429 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1878944 + ... + 1879593.

It is an arithmetic number, because the mean of its divisors is an integer number (135933791).

Almost surely, 2^1221524525 is an apocalyptic number.

It is an amenable number.

1221524525 is a deficient number, since it is larger than the sum of its proper divisors (409680967).

1221524525 is a wasteful number, since it uses less digits than its factorization.

1221524525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3758560 (or 3758555 counting only the distinct ones).

The product of its digits is 8000, while the sum is 29.

The square root of 1221524525 is about 34950.3150915696. The cubic root of 1221524525 is about 1068.9746269300.

Adding to 1221524525 its reverse (5254251221), we get a palindrome (6475775746).

The spelling of 1221524525 in words is "one billion, two hundred twenty-one million, five hundred twenty-four thousand, five hundred twenty-five".