261897856 has 32 divisors (see below), whose sum is σ = 569184480. Its totient is φ = 119043840.

The previous prime is 261897851. The next prime is 261897859. The reversal of 261897856 is 658798162.

261897856 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (32).

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 3 ways as a sum of consecutive naturals, for example, 91596 + ... + 94411.

It is an arithmetic number, because the mean of its divisors is an integer number (17787015).

Almost surely, 2^261897856 is an apocalyptic number.

It is an amenable number.

261897856 is an abundant number, since it is smaller than the sum of its proper divisors (307286624).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261897856 is a wasteful number, since it uses less digits than its factorization.

261897856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 186032 (or 186020 counting only the distinct ones).

The product of its digits is 1451520, while the sum is 52.

The square root of 261897856 is about 16183.2585099540. The cubic root of 261897856 is about 639.7996247718.

The spelling of 261897856 in words is "two hundred sixty-one million, eight hundred ninety-seven thousand, eight hundred fifty-six".