78206257 has 2 divisors, whose sum is σ = 78206258. Its totient is φ = 78206256.

The previous prime is 78206251. The next prime is 78206263. The reversal of 78206257 is 75260287.

It is a balanced prime because it is at equal distance from previous prime (78206251) and next prime (78206263).

It can be written as a sum of positive squares in only one way, i.e., 43678881 + 34527376 = 6609^2 + 5876^2 .

It is an emirp because it is prime and its reverse (75260287) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78206257 - 2¹⁹ = 77681969 is a prime.

It is a super-2 number, since 2×78206257² = 12232437267900098, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78206251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39103128 + 39103129.

It is an arithmetic number, because the mean of its divisors is an integer number (39103129).

Almost surely, 2^78206257 is an apocalyptic number.

It is an amenable number.

78206257 is a deficient number, since it is larger than the sum of its proper divisors (1).

78206257 is an equidigital number, since it uses as much as digits as its factorization.

78206257 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 47040, while the sum is 37.

The square root of 78206257 is about 8843.4301602941. The cubic root of 78206257 is about 427.6421459979.

The spelling of 78206257 in words is "seventy-eight million, two hundred six thousand, two hundred fifty-seven".