66078641 has 2 divisors, whose sum is σ = 66078642. Its totient is φ = 66078640.

The previous prime is 66078629. The next prime is 66078647. The reversal of 66078641 is 14687066.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 62078641 + 4000000 = 7879^2 + 2000^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66078641 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 66078595 and 66078604.

It is not a weakly prime, because it can be changed into another prime (66078647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33039320 + 33039321.

It is an arithmetic number, because the mean of its divisors is an integer number (33039321).

Almost surely, 2^66078641 is an apocalyptic number.

It is an amenable number.

66078641 is a deficient number, since it is larger than the sum of its proper divisors (1).

66078641 is an equidigital number, since it uses as much as digits as its factorization.

66078641 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48384, while the sum is 38.

The square root of 66078641 is about 8128.8769827080. The cubic root of 66078641 is about 404.2844470190.

The spelling of 66078641 in words is "sixty-six million, seventy-eight thousand, six hundred forty-one".