261626855 has 16 divisors (see below), whose sum is σ = 379909440. Its totient is φ = 168847872.

The previous prime is 261626851. The next prime is 261626861. The reversal of 261626855 is 558626162.

It is a cyclic number.

It is not a de Polignac number, because 261626855 - 2² = 261626851 is a prime.

It is a super-2 number, since 2×261626855² = 136897222514382050, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261626851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 219260 + ... + 220449.

It is an arithmetic number, because the mean of its divisors is an integer number (23744340).

Almost surely, 2^261626855 is an apocalyptic number.

261626855 is a deficient number, since it is larger than the sum of its proper divisors (118282585).

261626855 is a wasteful number, since it uses less digits than its factorization.

261626855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 439738.

The product of its digits is 172800, while the sum is 41.

The square root of 261626855 is about 16174.8834617131. The cubic root of 261626855 is about 639.5788692713.

The spelling of 261626855 in words is "two hundred sixty-one million, six hundred twenty-six thousand, eight hundred fifty-five".