78660401 has 2 divisors, whose sum is σ = 78660402. Its totient is φ = 78660400.

The previous prime is 78660359. The next prime is 78660419. The reversal of 78660401 is 10406687.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 78499600 + 160801 = 8860^2 + 401^2 .

It is a cyclic number.

It is not a de Polignac number, because 78660401 - 2¹⁰ = 78659377 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (78660451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39330200 + 39330201.

It is an arithmetic number, because the mean of its divisors is an integer number (39330201).

Almost surely, 2^78660401 is an apocalyptic number.

It is an amenable number.

78660401 is a deficient number, since it is larger than the sum of its proper divisors (1).

78660401 is an equidigital number, since it uses as much as digits as its factorization.

78660401 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 78660401 is about 8869.0699061401. The cubic root of 78660401 is about 428.4683219848.

The spelling of 78660401 in words is "seventy-eight million, six hundred sixty thousand, four hundred one".