16432121 has 4 divisors (see below), whose sum is σ = 16577652. Its totient is φ = 16286592.

The previous prime is 16432111. The next prime is 16432123. The reversal of 16432121 is 12123461.

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 8620096 + 7812025 = 2936^2 + 2795^2 .

It is a cyclic number.

It is not a de Polignac number, because 16432121 - 2¹⁰ = 16431097 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 16432093 and 16432102.

It is not an unprimeable number, because it can be changed into a prime (16432123) 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, 72596 + ... + 72821.

It is an arithmetic number, because the mean of its divisors is an integer number (4144413).

Almost surely, 2^16432121 is an apocalyptic number.

It is an amenable number.

16432121 is a deficient number, since it is larger than the sum of its proper divisors (145531).

16432121 is a wasteful number, since it uses less digits than its factorization.

16432121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 145530.

The product of its digits is 288, while the sum is 20.

The square root of 16432121 is about 4053.6552640796. The cubic root of 16432121 is about 254.2325819307.

Adding to 16432121 its reverse (12123461), we get a palindrome (28555582).

The spelling of 16432121 in words is "sixteen million, four hundred thirty-two thousand, one hundred twenty-one".