78057281 has 2 divisors, whose sum is σ = 78057282. Its totient is φ = 78057280.

The previous prime is 78057269. The next prime is 78057283. The reversal of 78057281 is 18275087.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 53217025 + 24840256 = 7295^2 + 4984^2 .

It is a cyclic number.

It is not a de Polignac number, because 78057281 - 2¹⁰ = 78056257 is a prime.

It is a super-2 number, since 2×78057281² = 12185878234225922, which contains 22 as substring.

Together with 78057283, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (78057283) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39028640 + 39028641.

It is an arithmetic number, because the mean of its divisors is an integer number (39028641).

Almost surely, 2^78057281 is an apocalyptic number.

It is an amenable number.

78057281 is a deficient number, since it is larger than the sum of its proper divisors (1).

78057281 is an equidigital number, since it uses as much as digits as its factorization.

78057281 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31360, while the sum is 38.

The square root of 78057281 is about 8835.0031692128. The cubic root of 78057281 is about 427.3704332449.

The spelling of 78057281 in words is "seventy-eight million, fifty-seven thousand, two hundred eighty-one".