13421252021 has 4 divisors (see below), whose sum is σ = 14210737452. Its totient is φ = 12631766592.

The previous prime is 13421252011. The next prime is 13421252041. The reversal of 13421252021 is 12025212431.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9843417796 + 3577834225 = 99214^2 + 59815^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13421252021 is a prime.

It is a super-2 number, since 2×13421252021² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13421252011) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 394742690 + ... + 394742723.

It is an arithmetic number, because the mean of its divisors is an integer number (3552684363).

Almost surely, 2^13421252021 is an apocalyptic number.

It is an amenable number.

13421252021 is a deficient number, since it is larger than the sum of its proper divisors (789485431).

13421252021 is an equidigital number, since it uses as much as digits as its factorization.

13421252021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 789485430.

The product of its (nonzero) digits is 960, while the sum is 23.

Adding to 13421252021 its reverse (12025212431), we get a palindrome (25446464452).

The spelling of 13421252021 in words is "thirteen billion, four hundred twenty-one million, two hundred fifty-two thousand, twenty-one".