261444247 has 2 divisors, whose sum is σ = 261444248. Its totient is φ = 261444246.

The previous prime is 261444187. The next prime is 261444319. The reversal of 261444247 is 742444162.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261444247 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261444847) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130722123 + 130722124.

It is an arithmetic number, because the mean of its divisors is an integer number (130722124).

Almost surely, 2^261444247 is an apocalyptic number.

261444247 is a deficient number, since it is larger than the sum of its proper divisors (1).

261444247 is an equidigital number, since it uses as much as digits as its factorization.

261444247 is an evil number, because the sum of its binary digits is even.

The product of its digits is 43008, while the sum is 34.

The square root of 261444247 is about 16169.2376752895. The cubic root of 261444247 is about 639.4300321024.

The spelling of 261444247 in words is "two hundred sixty-one million, four hundred forty-four thousand, two hundred forty-seven".