69778561 has 2 divisors, whose sum is σ = 69778562. Its totient is φ = 69778560.

The previous prime is 69778547. The next prime is 69778601. The reversal of 69778561 is 16587796.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 50908225 + 18870336 = 7135^2 + 4344^2 .

It is a cyclic number.

It is not a de Polignac number, because 69778561 - 2⁵ = 69778529 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (69778531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34889280 + 34889281.

It is an arithmetic number, because the mean of its divisors is an integer number (34889281).

Almost surely, 2^69778561 is an apocalyptic number.

It is an amenable number.

69778561 is a deficient number, since it is larger than the sum of its proper divisors (1).

69778561 is an equidigital number, since it uses as much as digits as its factorization.

69778561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 635040, while the sum is 49.

The square root of 69778561 is about 8353.3562715833. The cubic root of 69778561 is about 411.6934931642.

The spelling of 69778561 in words is "sixty-nine million, seven hundred seventy-eight thousand, five hundred sixty-one".