16440681 has 8 divisors (see below), whose sum is σ = 23074720. Its totient is φ = 10383552.

The previous prime is 16440673. The next prime is 16440727. The reversal of 16440681 is 18604461.

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

It is not a de Polignac number, because 16440681 - 2³ = 16440673 is a prime.

It is a super-3 number, since 3×16440681³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16440601) 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, 144160 + ... + 144273.

It is an arithmetic number, because the mean of its divisors is an integer number (2884340).

Almost surely, 2^16440681 is an apocalyptic number.

It is an amenable number.

16440681 is a deficient number, since it is larger than the sum of its proper divisors (6634039).

16440681 is a wasteful number, since it uses less digits than its factorization.

16440681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 288455.

The product of its (nonzero) digits is 4608, while the sum is 30.

The square root of 16440681 is about 4054.7109638049. The cubic root of 16440681 is about 254.2767201387.

The spelling of 16440681 in words is "sixteen million, four hundred forty thousand, six hundred eighty-one".