261477287 has 2 divisors, whose sum is σ = 261477288. Its totient is φ = 261477286.

The previous prime is 261477257. The next prime is 261477329. The reversal of 261477287 is 782774162.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261477287 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261477247) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130738643 + 130738644.

It is an arithmetic number, because the mean of its divisors is an integer number (130738644).

Almost surely, 2^261477287 is an apocalyptic number.

261477287 is a deficient number, since it is larger than the sum of its proper divisors (1).

261477287 is an equidigital number, since it uses as much as digits as its factorization.

261477287 is an evil number, because the sum of its binary digits is even.

The product of its digits is 263424, while the sum is 44.

The square root of 261477287 is about 16170.2593362011. The cubic root of 261477287 is about 639.4569669443.

The spelling of 261477287 in words is "two hundred sixty-one million, four hundred seventy-seven thousand, two hundred eighty-seven".