16778121 has 8 divisors (see below), whose sum is σ = 23548320. Its totient is φ = 10596672.

The previous prime is 16778089. The next prime is 16778123. The reversal of 16778121 is 12187761.

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

It is not a de Polignac number, because 16778121 - 2⁵ = 16778089 is a prime.

It is not an unprimeable number, because it can be changed into a prime (16778123) 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, 147120 + ... + 147233.

It is an arithmetic number, because the mean of its divisors is an integer number (2943540).

Almost surely, 2^16778121 is an apocalyptic number.

It is an amenable number.

16778121 is a deficient number, since it is larger than the sum of its proper divisors (6770199).

16778121 is a wasteful number, since it uses less digits than its factorization.

16778121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 294375.

The product of its digits is 4704, while the sum is 33.

The square root of 16778121 is about 4096.1104721431. The cubic root of 16778121 is about 256.0046029853.

The spelling of 16778121 in words is "sixteen million, seven hundred seventy-eight thousand, one hundred twenty-one".