78539233 has 2 divisors, whose sum is σ = 78539234. Its totient is φ = 78539232.

The previous prime is 78539203. The next prime is 78539243. The reversal of 78539233 is 33293587.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51165409 + 27373824 = 7153^2 + 5232^2 .

It is an emirp because it is prime and its reverse (33293587) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78539233 - 2²⁵ = 44984801 is a prime.

It is a super-2 number, since 2×78539233² = 12336822240456578, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78539203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39269616 + 39269617.

It is an arithmetic number, because the mean of its divisors is an integer number (39269617).

Almost surely, 2^78539233 is an apocalyptic number.

It is an amenable number.

78539233 is a deficient number, since it is larger than the sum of its proper divisors (1).

78539233 is an equidigital number, since it uses as much as digits as its factorization.

78539233 is an evil number, because the sum of its binary digits is even.

The product of its digits is 136080, while the sum is 40.

The square root of 78539233 is about 8862.2363430457. The cubic root of 78539233 is about 428.2482055976.

The spelling of 78539233 in words is "seventy-eight million, five hundred thirty-nine thousand, two hundred thirty-three".