16881985 has 4 divisors (see below), whose sum is σ = 20258388. Its totient is φ = 13505584.

The previous prime is 16881979. The next prime is 16881989. The reversal of 16881985 is 58918861.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2259009 + 14622976 = 1503^2 + 3824^2 .

It is a cyclic number.

It is not a de Polignac number, because 16881985 - 2¹¹ = 16879937 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16881989) 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, 1688194 + ... + 1688203.

It is an arithmetic number, because the mean of its divisors is an integer number (5064597).

Almost surely, 2^16881985 is an apocalyptic number.

It is an amenable number.

16881985 is a deficient number, since it is larger than the sum of its proper divisors (3376403).

16881985 is an equidigital number, since it uses as much as digits as its factorization.

16881985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3376402.

The product of its digits is 138240, while the sum is 46.

The square root of 16881985 is about 4108.7692804537. The cubic root of 16881985 is about 256.5317772885.

It can be divided in two parts, 1688198 and 5, that added together give a triangular number (1688203 = T₁₈₃₇).

The spelling of 16881985 in words is "sixteen million, eight hundred eighty-one thousand, nine hundred eighty-five".