261857086495 has 8 divisors (see below), whose sum is σ = 317759161680. Its totient is φ = 207131897280.

The previous prime is 261857086481. The next prime is 261857086559. The reversal of 261857086495 is 594680758162.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 261857086495 - 2¹⁵ = 261857053727 is a prime.

It is a super-2 number, since 2×261857086495² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 294221001 + ... + 294221890.

It is an arithmetic number, because the mean of its divisors is an integer number (39719895210).

Almost surely, 2^261857086495 is an apocalyptic number.

261857086495 is a deficient number, since it is larger than the sum of its proper divisors (55902075185).

261857086495 is an equidigital number, since it uses as much as digits as its factorization.

261857086495 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 588442985.

The product of its (nonzero) digits is 29030400, while the sum is 61.

The spelling of 261857086495 in words is "two hundred sixty-one billion, eight hundred fifty-seven million, eighty-six thousand, four hundred ninety-five".