16421717 has 4 divisors (see below), whose sum is σ = 17684940. Its totient is φ = 15158496.

The previous prime is 16421707. The next prime is 16421731. The reversal of 16421717 is 71712461.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 71712461 = 571 ⋅125591.

It can be written as a sum of positive squares in 2 ways, for example, as 6599761 + 9821956 = 2569^2 + 3134^2 .

It is a cyclic number.

It is not a de Polignac number, because 16421717 - 2¹⁶ = 16356181 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 16421717.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16421707) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 631592 + ... + 631617.

It is an arithmetic number, because the mean of its divisors is an integer number (4421235).

Almost surely, 2^16421717 is an apocalyptic number.

It is an amenable number.

16421717 is a deficient number, since it is larger than the sum of its proper divisors (1263223).

16421717 is a wasteful number, since it uses less digits than its factorization.

16421717 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1263222.

The product of its digits is 2352, while the sum is 29.

The square root of 16421717 is about 4052.3717746525. The cubic root of 16421717 is about 254.1789148029.

The spelling of 16421717 in words is "sixteen million, four hundred twenty-one thousand, seven hundred seventeen".