1210521221 has 16 divisors (see below), whose sum is σ = 1490893824. Its totient is φ = 957118464.

The previous prime is 1210521203. The next prime is 1210521233. The reversal of 1210521221 is 1221250121.

It is a cyclic number.

It is not a de Polignac number, because 1210521221 - 2¹⁰ = 1210520197 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1210521221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1210521421) 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, 162245 + ... + 169541.

It is an arithmetic number, because the mean of its divisors is an integer number (93180864).

Almost surely, 2^1210521221 is an apocalyptic number.

It is an amenable number.

1210521221 is a deficient number, since it is larger than the sum of its proper divisors (280372603).

1210521221 is a wasteful number, since it uses less digits than its factorization.

1210521221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9140.

The product of its (nonzero) digits is 80, while the sum is 17.

The square root of 1210521221 is about 34792.5454803181. The cubic root of 1210521221 is about 1065.7552214862.

Adding to 1210521221 its reverse (1221250121), we get a palindrome (2431771342).

The spelling of 1210521221 in words is "one billion, two hundred ten million, five hundred twenty-one thousand, two hundred twenty-one".