13721428 has 24 divisors (see below), whose sum is σ = 27524672. Its totient is φ = 5863104.

The previous prime is 13721423. The next prime is 13721441. The reversal of 13721428 is 82412731.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a junction number, because it is equal to n+sod(n) for n = 13721396 and 13721405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13721423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14176 + ... + 15112.

Almost surely, 2^13721428 is an apocalyptic number.

It is an amenable number.

13721428 is an abundant number, since it is smaller than the sum of its proper divisors (13803244).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

13721428 is a wasteful number, since it uses less digits than its factorization.

13721428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1471 (or 1469 counting only the distinct ones).

The product of its digits is 2688, while the sum is 28.

The square root of 13721428 is about 3704.2445923562. The cubic root of 13721428 is about 239.4049378441.

The spelling of 13721428 in words is "thirteen million, seven hundred twenty-one thousand, four hundred twenty-eight".