16013621 has 4 divisors (see below), whose sum is σ = 17245452. Its totient is φ = 14781792.

The previous prime is 16013611. The next prime is 16013623. The reversal of 16013621 is 12631061.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12631061 = 2273 ⋅5557.

It can be written as a sum of positive squares in 2 ways, for example, as 10491121 + 5522500 = 3239^2 + 2350^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16013621 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 16013593 and 16013602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16013623) 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 3 ways as a sum of consecutive naturals, for example, 615896 + ... + 615921.

It is an arithmetic number, because the mean of its divisors is an integer number (4311363).

Almost surely, 2^16013621 is an apocalyptic number.

It is an amenable number.

16013621 is a deficient number, since it is larger than the sum of its proper divisors (1231831).

16013621 is a wasteful number, since it uses less digits than its factorization.

16013621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1231830.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 16013621 is about 4001.7022627877. The cubic root of 16013621 is about 252.0556954666.

Adding to 16013621 its reverse (12631061), we get a palindrome (28644682).

The spelling of 16013621 in words is "sixteen million, thirteen thousand, six hundred twenty-one".