16855861 has 4 divisors (see below), whose sum is σ = 18388224. Its totient is φ = 15323500.

The previous prime is 16855829. The next prime is 16855877.

16855861 is nontrivially palindromic in base 10.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 16855861 - 2⁵ = 16855829 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16855801) 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, 766165 + ... + 766186.

It is an arithmetic number, because the mean of its divisors is an integer number (4597056).

Almost surely, 2^16855861 is an apocalyptic number.

16855861 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

16855861 is a deficient number, since it is larger than the sum of its proper divisors (1532363).

16855861 is a wasteful number, since it uses less digits than its factorization.

16855861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1532362.

The product of its digits is 57600, while the sum is 40.

The square root of 16855861 is about 4105.5889955036. The cubic root of 16855861 is about 256.3993857493.

The spelling of 16855861 in words is "sixteen million, eight hundred fifty-five thousand, eight hundred sixty-one".