1222220215521 has 6 divisors (see below), whose sum is σ = 1765429200210. Its totient is φ = 814813477008.

The previous prime is 1222220215483. The next prime is 1222220215547. The reversal of 1222220215521 is 1255120222221.

1222220215521 is a `hidden beast` number, since 1 + 222 + 220 + 215 + 5 + 2 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1074406879296 + 147813336225 = 1036536^2 + 384465^2 .

It is not a de Polignac number, because 1222220215521 - 2⁶ = 1222220215457 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1222220215591) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 67901123076 + ... + 67901123093.

It is an arithmetic number, because the mean of its divisors is an integer number (294238200035).

Almost surely, 2^{1222220215521} is an apocalyptic number.

It is an amenable number.

1222220215521 is a deficient number, since it is larger than the sum of its proper divisors (543208984689).

1222220215521 is a wasteful number, since it uses less digits than its factorization.

1222220215521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135802246175 (or 135802246172 counting only the distinct ones).

The product of its (nonzero) digits is 3200, while the sum is 27.

Adding to 1222220215521 its reverse (1255120222221), we get a palindrome (2477340437742).

The spelling of 1222220215521 in words is "one trillion, two hundred twenty-two billion, two hundred twenty million, two hundred fifteen thousand, five hundred twenty-one".