1211235221 has 16 divisors (see below), whose sum is σ = 1414091520. Its totient is φ = 1016050560.

The previous prime is 1211235211. The next prime is 1211235229. The reversal of 1211235221 is 1225321121.

It is a de Polignac number, because none of the positive numbers 2^k-1211235221 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1211235193 and 1211235202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211235229) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 59195 + ... + 76983.

It is an arithmetic number, because the mean of its divisors is an integer number (88380720).

Almost surely, 2^1211235221 is an apocalyptic number.

It is an amenable number.

1211235221 is a deficient number, since it is larger than the sum of its proper divisors (202856299).

1211235221 is a wasteful number, since it uses less digits than its factorization.

1211235221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18004.

The product of its digits is 240, while the sum is 20.

The square root of 1211235221 is about 34802.8047863962. The cubic root of 1211235221 is about 1065.9647179285.

Adding to 1211235221 its reverse (1225321121), we get a palindrome (2436556342).

The spelling of 1211235221 in words is "one billion, two hundred eleven million, two hundred thirty-five thousand, two hundred twenty-one".