1221231310525 has 12 divisors (see below), whose sum is σ = 1551261626964. Its totient is φ = 953156144000.

The previous prime is 1221231310513. The next prime is 1221231310543. The reversal of 1221231310525 is 5250131321221.

It can be written as a sum of positive squares in 6 ways, for example, as 406894721689 + 814336588836 = 637883^2 + 902406^2 .

It is not a de Polignac number, because 1221231310525 - 2¹¹ = 1221231308477 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1221231310493 and 1221231310502.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 595721566 + ... + 595723615.

It is an arithmetic number, because the mean of its divisors is an integer number (129271802247).

Almost surely, 2^{1221231310525} is an apocalyptic number.

It is an amenable number.

1221231310525 is a deficient number, since it is larger than the sum of its proper divisors (330030316439).

1221231310525 is a wasteful number, since it uses less digits than its factorization.

1221231310525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1191445232 (or 1191445227 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 28.

Adding to 1221231310525 its reverse (5250131321221), we get a palindrome (6471362631746).

The spelling of 1221231310525 in words is "one trillion, two hundred twenty-one billion, two hundred thirty-one million, three hundred ten thousand, five hundred twenty-five".