13722021 has 8 divisors (see below), whose sum is σ = 20328960. Its totient is φ = 9147996.

The previous prime is 13722019. The next prime is 13722067. The reversal of 13722021 is 12022731.

It is not a de Polignac number, because 13722021 - 2¹ = 13722019 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 13721985 and 13722003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13722091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 254085 + ... + 254138.

It is an arithmetic number, because the mean of its divisors is an integer number (2541120).

Almost surely, 2^13722021 is an apocalyptic number.

It is an amenable number.

13722021 is a deficient number, since it is larger than the sum of its proper divisors (6606939).

13722021 is an equidigital number, since it uses as much as digits as its factorization.

13722021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 508232 (or 508226 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 18.

The square root of 13722021 is about 3704.3246348019. The cubic root of 13722021 is about 239.4083865882.

Adding to 13722021 its reverse (12022731), we get a palindrome (25744752).

The spelling of 13722021 in words is "thirteen million, seven hundred twenty-two thousand, twenty-one".