21616069 has 2 divisors, whose sum is σ = 21616070. Its totient is φ = 21616068.

The previous prime is 21616051. The next prime is 21616073. The reversal of 21616069 is 96061612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13235044 + 8381025 = 3638^2 + 2895^2 .

It is a cyclic number.

It is not a de Polignac number, because 21616069 - 2⁷ = 21615941 is a prime.

It is a super-2 number, since 2×21616069² = 934508878025522, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21616069.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21616019) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10808034 + 10808035.

It is an arithmetic number, because the mean of its divisors is an integer number (10808035).

Almost surely, 2^21616069 is an apocalyptic number.

It is an amenable number.

21616069 is a deficient number, since it is larger than the sum of its proper divisors (1).

21616069 is an equidigital number, since it uses as much as digits as its factorization.

21616069 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3888, while the sum is 31.

The square root of 21616069 is about 4649.3084431988. The cubic root of 21616069 is about 278.5643737232.

The spelling of 21616069 in words is "twenty-one million, six hundred sixteen thousand, sixty-nine".