16218381 has 32 divisors (see below), whose sum is σ = 24192000. Its totient is φ = 9618048.

The previous prime is 16218373. The next prime is 16218401. The reversal of 16218381 is 18381261.

It is not a de Polignac number, because 16218381 - 2³ = 16218373 is a prime.

It is a super-2 number, since 2×16218381² = 526071764522322, which contains 22 as substring.

It is a plaindrome in base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16218331) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 116610 + ... + 116748.

It is an arithmetic number, because the mean of its divisors is an integer number (756000).

Almost surely, 2^16218381 is an apocalyptic number.

It is an amenable number.

16218381 is a deficient number, since it is larger than the sum of its proper divisors (7973619).

16218381 is a wasteful number, since it uses less digits than its factorization.

16218381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 273.

The product of its digits is 2304, while the sum is 30.

The square root of 16218381 is about 4027.2051102471. The cubic root of 16218381 is about 253.1254617885.

The spelling of 16218381 in words is "sixteen million, two hundred eighteen thousand, three hundred eighty-one".