261572566 has 8 divisors (see below), whose sum is σ = 392529600. Its totient is φ = 130729368.

The previous prime is 261572561. The next prime is 261572567. The reversal of 261572566 is 665275162.

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 (261572561) 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, 22461 + ... + 32056.

It is an arithmetic number, because the mean of its divisors is an integer number (49066200).

Almost surely, 2^261572566 is an apocalyptic number.

261572566 is a deficient number, since it is larger than the sum of its proper divisors (130957034).

261572566 is a wasteful number, since it uses less digits than its factorization.

261572566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56918.

The product of its digits is 151200, while the sum is 40.

The square root of 261572566 is about 16173.2051863568. The cubic root of 261572566 is about 639.5346275093.

The spelling of 261572566 in words is "two hundred sixty-one million, five hundred seventy-two thousand, five hundred sixty-six".