16887621 has 4 divisors (see below), whose sum is σ = 22516832. Its totient is φ = 11258412.

The previous prime is 16887583. The next prime is 16887623. The reversal of 16887621 is 12678861.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 16887621 - 2⁶ = 16887557 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 16887621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16887623) 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 3 ways as a sum of consecutive naturals, for example, 2814601 + ... + 2814606.

It is an arithmetic number, because the mean of its divisors is an integer number (5629208).

Almost surely, 2^16887621 is an apocalyptic number.

It is an amenable number.

16887621 is a deficient number, since it is larger than the sum of its proper divisors (5629211).

16887621 is an equidigital number, since it uses as much as digits as its factorization.

16887621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5629210.

The product of its digits is 32256, while the sum is 39.

The square root of 16887621 is about 4109.4550733644. The cubic root of 16887621 is about 256.5603215668.

The spelling of 16887621 in words is "sixteen million, eight hundred eighty-seven thousand, six hundred twenty-one".