16121 has 8 divisors (see below), whose sum is σ = 19200. Its totient is φ = 13524.

The previous prime is 16111. The next prime is 16127. The reversal of 16121 is 12161.

It is not a de Polignac number, because 16121 - 2⁶ = 16057 is a prime.

It is an Ulam number.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a plaindrome in base 11.

It is a nialpdrome in base 7.

It is not an unprimeable number, because it can be changed into a prime (16127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 320 + ... + 366.

It is an arithmetic number, because the mean of its divisors is an integer number (2400).

2¹⁶¹²¹ is an apocalyptic number.

It is an amenable number.

16121 is a deficient number, since it is larger than the sum of its proper divisors (3079).

16121 is an frugal number, since it uses more digits than its factorization.

It is an anagram of its base 11 representation: 16121 = (11126)₁₁.

16121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68 (or 54 counting only the distinct ones).

The product of its digits is 12, while the sum is 11.

The square root of 16121 is about 126.9685000305. The cubic root of 16121 is about 25.2617825610.

Subtracting from 16121 its sum of digits (11), we obtain a triangular number (16110 = T₁₇₉).

Adding to 16121 its reverse (12161), we get a palindrome (28282).

It can be divided in two parts, 16 and 121, that multiplied together give a square (1936 = 44²).

The spelling of 16121 in words is "sixteen thousand, one hundred twenty-one".