13121331021 has 12 divisors (see below), whose sum is σ = 19654998272. Its totient is φ = 8747553852.

The previous prime is 13121330951. The next prime is 13121331029. The reversal of 13121331021 is 12013312131.

13121331021 is a `hidden beast` number, since 1 + 312 + 1 + 331 + 0 + 21 = 666.

It is not a de Polignac number, because 13121331021 - 2¹¹ = 13121328973 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 13121330985 and 13121331003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13121331029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 26998381 + ... + 26998866.

Almost surely, 2^13121331021 is an apocalyptic number.

It is an amenable number.

13121331021 is a deficient number, since it is larger than the sum of its proper divisors (6533667251).

13121331021 is an frugal number, since it uses more digits than its factorization.

13121331021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53997262 (or 53997250 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 18.

Adding to 13121331021 its reverse (12013312131), we get a palindrome (25134643152).

The spelling of 13121331021 in words is "thirteen billion, one hundred twenty-one million, three hundred thirty-one thousand, twenty-one".