261026566 has 8 divisors (see below), whose sum is σ = 393250320. Its totient is φ = 129943128.

The previous prime is 261026543. The next prime is 261026569. The reversal of 261026566 is 665620162.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261026569) 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, 284506 + ... + 285421.

It is an arithmetic number, because the mean of its divisors is an integer number (49156290).

Almost surely, 2^261026566 is an apocalyptic number.

261026566 is a deficient number, since it is larger than the sum of its proper divisors (132223754).

261026566 is a wasteful number, since it uses less digits than its factorization.

261026566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 570158.

The product of its (nonzero) digits is 25920, while the sum is 34.

The square root of 261026566 is about 16156.3165975417. The cubic root of 261026566 is about 639.0893346985.

The spelling of 261026566 in words is "two hundred sixty-one million, twenty-six thousand, five hundred sixty-six".