16938921 has 8 divisors (see below), whose sum is σ = 22619520. Its totient is φ = 11275472.

The previous prime is 16938917. The next prime is 16938931. The reversal of 16938921 is 12983961.

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

It is a cyclic number.

It is not a de Polignac number, because 16938921 - 2² = 16938917 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 16938921.

It is not an unprimeable number, because it can be changed into a prime (16938931) 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, 1770 + ... + 6083.

It is an arithmetic number, because the mean of its divisors is an integer number (2827440).

Almost surely, 2^16938921 is an apocalyptic number.

It is an amenable number.

16938921 is a deficient number, since it is larger than the sum of its proper divisors (5680599).

16938921 is an equidigital number, since it uses as much as digits as its factorization.

16938921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8575.

The product of its digits is 23328, while the sum is 39.

The square root of 16938921 is about 4115.6920438731. The cubic root of 16938921 is about 256.8198457843.

The spelling of 16938921 in words is "sixteen million, nine hundred thirty-eight thousand, nine hundred twenty-one".