16981566 has 16 divisors (see below), whose sum is σ = 38815104. Its totient is φ = 4851864.

The previous prime is 16981553. The next prime is 16981577. The reversal of 16981566 is 66518961.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (42), and also a Moran number because the ratio is a prime number: 404323 = 16981566 / (1 + 6 + 9 + 8 + 1 + 5 + 6 + 6).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 202120 + ... + 202203.

It is an arithmetic number, because the mean of its divisors is an integer number (2425944).

Almost surely, 2^16981566 is an apocalyptic number.

16981566 is an abundant number, since it is smaller than the sum of its proper divisors (21833538).

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

16981566 is a wasteful number, since it uses less digits than its factorization.

16981566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 404335.

The product of its digits is 77760, while the sum is 42.

The square root of 16981566 is about 4120.8695684285. The cubic root of 16981566 is about 257.0351862274.

The spelling of 16981566 in words is "sixteen million, nine hundred eighty-one thousand, five hundred sixty-six".