261897855 has 8 divisors (see below), whose sum is σ = 419036592. Its totient is φ = 139678848.

The previous prime is 261897851. The next prime is 261897859. The reversal of 261897855 is 558798162.

It is an interprime number because it is at equal distance from previous prime (261897851) and next prime (261897859).

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

It is not a de Polignac number, because 261897855 - 2² = 261897851 is a prime.

It is a zygodrome in base 2.

It is a junction number, because it is equal to n+sod(n) for n = 261897798 and 261897807.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261897851) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8729914 + ... + 8729943.

It is an arithmetic number, because the mean of its divisors is an integer number (52379574).

Almost surely, 2^261897855 is an apocalyptic number.

261897855 is a deficient number, since it is larger than the sum of its proper divisors (157138737).

261897855 is a wasteful number, since it uses less digits than its factorization.

261897855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17459865.

The product of its digits is 1209600, while the sum is 51.

The square root of 261897855 is about 16183.2584790579. The cubic root of 261897855 is about 639.7996239575.

The spelling of 261897855 in words is "two hundred sixty-one million, eight hundred ninety-seven thousand, eight hundred fifty-five".