561778247 has 2 divisors, whose sum is σ = 561778248. Its totient is φ = 561778246.

The previous prime is 561778223. The next prime is 561778253. The reversal of 561778247 is 742877165.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 561778247 - 2¹² = 561774151 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (561778297) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 280889123 + 280889124.

It is an arithmetic number, because the mean of its divisors is an integer number (280889124).

Almost surely, 2^561778247 is an apocalyptic number.

561778247 is a deficient number, since it is larger than the sum of its proper divisors (1).

561778247 is an equidigital number, since it uses as much as digits as its factorization.

561778247 is an evil number, because the sum of its binary digits is even.

The product of its digits is 658560, while the sum is 47.

The square root of 561778247 is about 23701.8616779358. The cubic root of 561778247 is about 825.1285980129.

The spelling of 561778247 in words is "five hundred sixty-one million, seven hundred seventy-eight thousand, two hundred forty-seven".