1211152521 has 4 divisors (see below), whose sum is σ = 1614870032. Its totient is φ = 807435012.

The previous prime is 1211152507. The next prime is 1211152529. The reversal of 1211152521 is 1252511121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1252511121 = 3 ⋅417503707.

It is not a de Polignac number, because 1211152521 - 2¹⁰ = 1211151497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1211152529) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 201858751 + ... + 201858756.

It is an arithmetic number, because the mean of its divisors is an integer number (403717508).

Almost surely, 2^1211152521 is an apocalyptic number.

It is an amenable number.

1211152521 is a deficient number, since it is larger than the sum of its proper divisors (403717511).

1211152521 is an equidigital number, since it uses as much as digits as its factorization.

1211152521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 403717510.

The product of its digits is 200, while the sum is 21.

The square root of 1211152521 is about 34801.6166434837. The cubic root of 1211152521 is about 1065.9404569408.

Adding to 1211152521 its reverse (1252511121), we get a palindrome (2463663642).

The spelling of 1211152521 in words is "one billion, two hundred eleven million, one hundred fifty-two thousand, five hundred twenty-one".