13771251221 has 32 divisors (see below), whose sum is σ = 17438416128. Its totient is φ = 10585935360.

The previous prime is 13771251211. The next prime is 13771251271. The reversal of 13771251221 is 12215217731.

13771251221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a de Polignac number, because none of the positive numbers 2^k-13771251221 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13771251211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 429611 + ... + 460551.

It is an arithmetic number, because the mean of its divisors is an integer number (544950504).

Almost surely, 2^13771251221 is an apocalyptic number.

It is an amenable number.

13771251221 is a deficient number, since it is larger than the sum of its proper divisors (3667164907).

13771251221 is a wasteful number, since it uses less digits than its factorization.

13771251221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31101.

The product of its digits is 5880, while the sum is 32.

Adding to 13771251221 its reverse (12215217731), we get a palindrome (25986468952).

The spelling of 13771251221 in words is "thirteen billion, seven hundred seventy-one million, two hundred fifty-one thousand, two hundred twenty-one".