16121309 has 2 divisors, whose sum is σ = 16121310. Its totient is φ = 16121308.

The previous prime is 16121279. The next prime is 16121311. The reversal of 16121309 is 90312161.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16080100 + 41209 = 4010^2 + 203^2 .

It is an emirp because it is prime and its reverse (90312161) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16121309 - 2¹⁶ = 16055773 is a prime.

Together with 16121311, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16121509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8060654 + 8060655.

It is an arithmetic number, because the mean of its divisors is an integer number (8060655).

Almost surely, 2^16121309 is an apocalyptic number.

It is an amenable number.

16121309 is a deficient number, since it is larger than the sum of its proper divisors (1).

16121309 is an equidigital number, since it uses as much as digits as its factorization.

16121309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 324, while the sum is 23.

The square root of 16121309 is about 4015.1349915040. The cubic root of 16121309 is about 252.6194396206.

The spelling of 16121309 in words is "sixteen million, one hundred twenty-one thousand, three hundred nine".