261158566 has 8 divisors (see below), whose sum is σ = 393726960. Its totient is φ = 129916248.

The previous prime is 261158549. The next prime is 261158567. The reversal of 261158566 is 665851162.

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 (261158567) 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, 331026 + ... + 331813.

It is an arithmetic number, because the mean of its divisors is an integer number (49215870).

Almost surely, 2^261158566 is an apocalyptic number.

261158566 is a deficient number, since it is larger than the sum of its proper divisors (132568394).

261158566 is a wasteful number, since it uses less digits than its factorization.

261158566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 663038.

The product of its digits is 86400, while the sum is 40.

The square root of 261158566 is about 16160.4011707631. The cubic root of 261158566 is about 639.1970447774.

The spelling of 261158566 in words is "two hundred sixty-one million, one hundred fifty-eight thousand, five hundred sixty-six".