16721117 has 8 divisors (see below), whose sum is σ = 19202112. Its totient is φ = 14263200.

The previous prime is 16721093. The next prime is 16721119. The reversal of 16721117 is 71112761.

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

It is not a de Polignac number, because 16721117 - 2¹⁸ = 16458973 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16721119) 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, 4184 + ... + 7137.

It is an arithmetic number, because the mean of its divisors is an integer number (2400264).

Almost surely, 2^16721117 is an apocalyptic number.

It is an amenable number.

16721117 is a deficient number, since it is larger than the sum of its proper divisors (2480995).

16721117 is a wasteful number, since it uses less digits than its factorization.

16721117 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11539.

The product of its digits is 588, while the sum is 26.

The square root of 16721117 is about 4089.1462434107. The cubic root of 16721117 is about 255.7143471088.

Adding to 16721117 its reverse (71112761), we get a palindrome (87833878).

The spelling of 16721117 in words is "sixteen million, seven hundred twenty-one thousand, one hundred seventeen".