261380566 has 8 divisors (see below), whose sum is σ = 392250600. Its totient is φ = 130630368.

The previous prime is 261380513. The next prime is 261380569. The reversal of 261380566 is 665083162.

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 (261380569) 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, 24291 + ... + 33358.

It is an arithmetic number, because the mean of its divisors is an integer number (49031325).

Almost surely, 2^261380566 is an apocalyptic number.

261380566 is a deficient number, since it is larger than the sum of its proper divisors (130870034).

261380566 is a wasteful number, since it uses less digits than its factorization.

261380566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59918.

The product of its (nonzero) digits is 51840, while the sum is 37.

The square root of 261380566 is about 16167.2683530645. The cubic root of 261380566 is about 639.3781117269.

The spelling of 261380566 in words is "two hundred sixty-one million, three hundred eighty thousand, five hundred sixty-six".