78209563 has 2 divisors, whose sum is σ = 78209564. Its totient is φ = 78209562.

The previous prime is 78209543. The next prime is 78209581. The reversal of 78209563 is 36590287.

It is a strong prime.

It is an emirp because it is prime and its reverse (36590287) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78209563 is a prime.

It is a super-2 number, since 2×78209563² = 12233471489301938, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78209533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39104781 + 39104782.

It is an arithmetic number, because the mean of its divisors is an integer number (39104782).

Almost surely, 2^78209563 is an apocalyptic number.

78209563 is a deficient number, since it is larger than the sum of its proper divisors (1).

78209563 is an equidigital number, since it uses as much as digits as its factorization.

78209563 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 90720, while the sum is 40.

The square root of 78209563 is about 8843.6170767396. The cubic root of 78209563 is about 427.6481717946.

The spelling of 78209563 in words is "seventy-eight million, two hundred nine thousand, five hundred sixty-three".