13121021 has 8 divisors (see below), whose sum is σ = 13621080. Its totient is φ = 12624192.

The previous prime is 13120999. The next prime is 13121033. The reversal of 13121021 is 12012131.

It can be written as a sum of positive squares in 4 ways, for example, as 240100 + 12880921 = 490^2 + 3589^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13121021 is a prime.

It is a super-2 number, since 2×13121021² = 344322384164882, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 13120993 and 13121011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13121041) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10211 + ... + 11423.

It is an arithmetic number, because the mean of its divisors is an integer number (1702635).

Almost surely, 2^13121021 is an apocalyptic number.

It is an amenable number.

13121021 is a deficient number, since it is larger than the sum of its proper divisors (500059).

13121021 is a wasteful number, since it uses less digits than its factorization.

13121021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1615.

The product of its (nonzero) digits is 12, while the sum is 11.

The square root of 13121021 is about 3622.2949907483. The cubic root of 13121021 is about 235.8608595217.

Adding to 13121021 its reverse (12012131), we get a palindrome (25133152).

The spelling of 13121021 in words is "thirteen million, one hundred twenty-one thousand, twenty-one".