78074561 has 2 divisors, whose sum is σ = 78074562. Its totient is φ = 78074560.

The previous prime is 78074539. The next prime is 78074569. The reversal of 78074561 is 16547087.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 59969536 + 18105025 = 7744^2 + 4255^2 .

It is a cyclic number.

It is not a de Polignac number, because 78074561 - 2¹⁴ = 78058177 is a prime.

It is not a weakly prime, because it can be changed into another prime (78074569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39037280 + 39037281.

It is an arithmetic number, because the mean of its divisors is an integer number (39037281).

Almost surely, 2^78074561 is an apocalyptic number.

It is an amenable number.

78074561 is a deficient number, since it is larger than the sum of its proper divisors (1).

78074561 is an equidigital number, since it uses as much as digits as its factorization.

78074561 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 38.

The square root of 78074561 is about 8835.9810434382. The cubic root of 78074561 is about 427.4019674213.

The spelling of 78074561 in words is "seventy-eight million, seventy-four thousand, five hundred sixty-one".