216367409 has 2 divisors, whose sum is σ = 216367410. Its totient is φ = 216367408.

The previous prime is 216367391. The next prime is 216367429. The reversal of 216367409 is 904763612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 203205025 + 13162384 = 14255^2 + 3628^2 .

It is a cyclic number.

It is not a de Polignac number, because 216367409 - 2¹⁶ = 216301873 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (216367429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108183704 + 108183705.

It is an arithmetic number, because the mean of its divisors is an integer number (108183705).

Almost surely, 2^216367409 is an apocalyptic number.

It is an amenable number.

216367409 is a deficient number, since it is larger than the sum of its proper divisors (1).

216367409 is an equidigital number, since it uses as much as digits as its factorization.

216367409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 54432, while the sum is 38.

The square root of 216367409 is about 14709.4326539129. The cubic root of 216367409 is about 600.3400008145.

The spelling of 216367409 in words is "two hundred sixteen million, three hundred sixty-seven thousand, four hundred nine".