261870543287 has 24 divisors (see below), whose sum is σ = 285124404096. Its totient is φ = 240297637824.

The previous prime is 261870543283. The next prime is 261870543299. The reversal of 261870543287 is 782345078162.

It is not a de Polignac number, because 261870543287 - 2² = 261870543283 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261870543283) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2934653 + ... + 3022569.

It is an arithmetic number, because the mean of its divisors is an integer number (11880183504).

Almost surely, 2^261870543287 is an apocalyptic number.

261870543287 is a deficient number, since it is larger than the sum of its proper divisors (23253860809).

261870543287 is a wasteful number, since it uses less digits than its factorization.

261870543287 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88215 (or 88196 counting only the distinct ones).

The product of its (nonzero) digits is 4515840, while the sum is 53.

The spelling of 261870543287 in words is "two hundred sixty-one billion, eight hundred seventy million, five hundred forty-three thousand, two hundred eighty-seven".