1211253003521 has 12 divisors (see below), whose sum is σ = 1377286833300. Its totient is φ = 1063168777440.

The previous prime is 1211253003511. The next prime is 1211253003557. The reversal of 1211253003521 is 1253003521121.

It can be written as a sum of positive squares in 2 ways, for example, as 320909787121 + 890343216400 = 566489^2 + 943580^2 .

It is not a de Polignac number, because 1211253003521 - 2²⁶ = 1211185894657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1211253003511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 172588826 + ... + 172595843.

It is an arithmetic number, because the mean of its divisors is an integer number (114773902775).

Almost surely, 2^{1211253003521} is an apocalyptic number.

1211253003521 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1211253003521 is a deficient number, since it is larger than the sum of its proper divisors (166033829779).

1211253003521 is a wasteful number, since it uses less digits than its factorization.

1211253003521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 345184720 (or 345184709 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 26.

Adding to 1211253003521 its reverse (1253003521121), we get a palindrome (2464256524642).

The spelling of 1211253003521 in words is "one trillion, two hundred eleven billion, two hundred fifty-three million, three thousand, five hundred twenty-one".