16636121 has 2 divisors, whose sum is σ = 16636122. Its totient is φ = 16636120.

The previous prime is 16636099. The next prime is 16636127. The reversal of 16636121 is 12163661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16491721 + 144400 = 4061^2 + 380^2 .

It is an emirp because it is prime and its reverse (12163661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16636121 - 2¹⁰ = 16635097 is a prime.

It is equal to p_1069361 and since 16636121 and 1069361 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (16636127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8318060 + 8318061.

It is an arithmetic number, because the mean of its divisors is an integer number (8318061).

Almost surely, 2^16636121 is an apocalyptic number.

It is an amenable number.

16636121 is a deficient number, since it is larger than the sum of its proper divisors (1).

16636121 is an equidigital number, since it uses as much as digits as its factorization.

16636121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1296, while the sum is 26.

The square root of 16636121 is about 4078.7401241070. The cubic root of 16636121 is about 255.2803324847.

Adding to 16636121 its reverse (12163661), we get a palindrome (28799782).

The spelling of 16636121 in words is "sixteen million, six hundred thirty-six thousand, one hundred twenty-one".