261826657 has 2 divisors, whose sum is σ = 261826658. Its totient is φ = 261826656.

The previous prime is 261826637. The next prime is 261826679. The reversal of 261826657 is 756628162.

261826657 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 235653201 + 26173456 = 15351^2 + 5116^2 .

It is a cyclic number.

It is not a de Polignac number, because 261826657 - 2¹¹ = 261824609 is a prime.

It is not a weakly prime, because it can be changed into another prime (261826637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130913328 + 130913329.

It is an arithmetic number, because the mean of its divisors is an integer number (130913329).

Almost surely, 2^261826657 is an apocalyptic number.

It is an amenable number.

261826657 is a deficient number, since it is larger than the sum of its proper divisors (1).

261826657 is an equidigital number, since it uses as much as digits as its factorization.

261826657 is an evil number, because the sum of its binary digits is even.

The product of its digits is 241920, while the sum is 43.

The square root of 261826657 is about 16181.0585871259. The cubic root of 261826657 is about 639.7416413239.

The spelling of 261826657 in words is "two hundred sixty-one million, eight hundred twenty-six thousand, six hundred fifty-seven".