21160309 has 2 divisors, whose sum is σ = 21160310. Its totient is φ = 21160308.

The previous prime is 21160301. The next prime is 21160313. The reversal of 21160309 is 90306112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18679684 + 2480625 = 4322^2 + 1575^2 .

It is a cyclic number.

It is not a de Polignac number, because 21160309 - 2³ = 21160301 is a prime.

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 21160309.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21160301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10580154 + 10580155.

It is an arithmetic number, because the mean of its divisors is an integer number (10580155).

Almost surely, 2^21160309 is an apocalyptic number.

It is an amenable number.

21160309 is a deficient number, since it is larger than the sum of its proper divisors (1).

21160309 is an equidigital number, since it uses as much as digits as its factorization.

21160309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 324, while the sum is 22.

The square root of 21160309 is about 4600.0335868339. The cubic root of 21160309 is about 276.5926711357.

The spelling of 21160309 in words is "twenty-one million, one hundred sixty thousand, three hundred nine".