13665021 has 8 divisors (see below), whose sum is σ = 18259104. Its totient is φ = 9090480.

The previous prime is 13665019. The next prime is 13665023. The reversal of 13665021 is 12056631.

13665021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (13665019) and next prime (13665023).

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

It is not a de Polignac number, because 13665021 - 2¹ = 13665019 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 13664982 and 13665000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13665023) 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, 3166 + ... + 6111.

It is an arithmetic number, because the mean of its divisors is an integer number (2282388).

Almost surely, 2^13665021 is an apocalyptic number.

It is an amenable number.

13665021 is a deficient number, since it is larger than the sum of its proper divisors (4594083).

13665021 is an equidigital number, since it uses as much as digits as its factorization.

13665021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9771.

The product of its (nonzero) digits is 1080, while the sum is 24.

The square root of 13665021 is about 3696.6229182864. The cubic root of 13665021 is about 239.0764331321.

The spelling of 13665021 in words is "thirteen million, six hundred sixty-five thousand, twenty-one".