16881978 has 8 divisors (see below), whose sum is σ = 33763968. Its totient is φ = 5627324.

The previous prime is 16881961. The next prime is 16881979. The reversal of 16881978 is 87918861.

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

16881978 is an admirable number.

It is a super-4 number, since 4×16881978⁴ (a number of 30 digits) contains 4444 as substring.

It is not an unprimeable number, because it can be changed into a prime (16881979) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1406826 + ... + 1406837.

It is an arithmetic number, because the mean of its divisors is an integer number (4220496).

Almost surely, 2^16881978 is an apocalyptic number.

16881978 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

16881978 is a wasteful number, since it uses less digits than its factorization.

16881978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2813668.

The product of its digits is 193536, while the sum is 48.

The square root of 16881978 is about 4108.7684286170. The cubic root of 16881978 is about 256.5317418321.

The spelling of 16881978 in words is "sixteen million, eight hundred eighty-one thousand, nine hundred seventy-eight".