16117921 has 8 divisors (see below), whose sum is σ = 17141760. Its totient is φ = 15102528.

The previous prime is 16117919. The next prime is 16117931. The reversal of 16117921 is 12971161.

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

It is not a de Polignac number, because 16117921 - 2¹ = 16117919 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 16117921.

It is not an unprimeable number, because it can be changed into a prime (16117931) 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 7 ways as a sum of consecutive naturals, for example, 2080 + ... + 6046.

It is an arithmetic number, because the mean of its divisors is an integer number (2142720).

Almost surely, 2^16117921 is an apocalyptic number.

It is an amenable number.

16117921 is a deficient number, since it is larger than the sum of its proper divisors (1023839).

16117921 is a wasteful number, since it uses less digits than its factorization.

16117921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4223.

The product of its digits is 756, while the sum is 28.

The square root of 16117921 is about 4014.7130657122. The cubic root of 16117921 is about 252.6017418306.

The spelling of 16117921 in words is "sixteen million, one hundred seventeen thousand, nine hundred twenty-one".