261606255 has 16 divisors (see below), whose sum is σ = 436769280. Its totient is φ = 133456928.

The previous prime is 261606253. The next prime is 261606259. The reversal of 261606255 is 552606162.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 261606255 - 2¹ = 261606253 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261606253) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 378795 + ... + 379484.

It is an arithmetic number, because the mean of its divisors is an integer number (27298080).

Almost surely, 2^261606255 is an apocalyptic number.

261606255 is a deficient number, since it is larger than the sum of its proper divisors (175163025).

261606255 is a wasteful number, since it uses less digits than its factorization.

261606255 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 758310.

The product of its (nonzero) digits is 21600, while the sum is 33.

The square root of 261606255 is about 16174.2466594274. The cubic root of 261606255 is about 639.5620824236.

The spelling of 261606255 in words is "two hundred sixty-one million, six hundred six thousand, two hundred fifty-five".