13123021221 has 16 divisors (see below), whose sum is σ = 19451752320. Its totient is φ = 8744073120.

The previous prime is 13123021189. The next prime is 13123021231. The reversal of 13123021221 is 12212032131.

It is not a de Polignac number, because 13123021221 - 2⁵ = 13123021189 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 13123021194 and 13123021203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13123021231) 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, 75385 + ... + 178686.

It is an arithmetic number, because the mean of its divisors is an integer number (1215734520).

Almost surely, 2^13123021221 is an apocalyptic number.

It is an amenable number.

13123021221 is a deficient number, since it is larger than the sum of its proper divisors (6328731099).

13123021221 is a wasteful number, since it uses less digits than its factorization.

13123021221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 255993 (or 255987 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 13123021221 its reverse (12212032131), we get a palindrome (25335053352).

The spelling of 13123021221 in words is "thirteen billion, one hundred twenty-three million, twenty-one thousand, two hundred twenty-one".