667178528561 has 2 divisors, whose sum is σ = 667178528562. Its totient is φ = 667178528560.

The previous prime is 667178528539. The next prime is 667178528573. The reversal of 667178528561 is 165825871766.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 666280387600 + 898140961 = 816260^2 + 29969^2 .

It is a cyclic number.

It is not a de Polignac number, because 667178528561 - 2¹⁰ = 667178527537 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 667178528494 and 667178528503.

It is not a weakly prime, because it can be changed into another prime (667178522561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333589264280 + 333589264281.

It is an arithmetic number, because the mean of its divisors is an integer number (333589264281).

Almost surely, 2^667178528561 is an apocalyptic number.

It is an amenable number.

667178528561 is a deficient number, since it is larger than the sum of its proper divisors (1).

667178528561 is an equidigital number, since it uses as much as digits as its factorization.

667178528561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 33868800, while the sum is 62.

The spelling of 667178528561 in words is "six hundred sixty-seven billion, one hundred seventy-eight million, five hundred twenty-eight thousand, five hundred sixty-one".