13404721 has 16 divisors (see below), whose sum is σ = 15664320. Its totient is φ = 11335680.

The previous prime is 13404697. The next prime is 13404733. The reversal of 13404721 is 12740431.

It is a cyclic number.

It is not a de Polignac number, because 13404721 - 2¹¹ = 13402673 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 13404692 and 13404701.

It is not an unprimeable number, because it can be changed into a prime (13404761) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17770 + ... + 18508.

It is an arithmetic number, because the mean of its divisors is an integer number (979020).

Almost surely, 2^13404721 is an apocalyptic number.

13404721 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

13404721 is a deficient number, since it is larger than the sum of its proper divisors (2259599).

13404721 is a wasteful number, since it uses less digits than its factorization.

13404721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 864.

The product of its (nonzero) digits is 672, while the sum is 22.

The square root of 13404721 is about 3661.2458262182. The cubic root of 13404721 is about 237.5486644507.

The spelling of 13404721 in words is "thirteen million, four hundred four thousand, seven hundred twenty-one".