261215081 has 8 divisors (see below), whose sum is σ = 276721920. Its totient is φ = 245723968.

The previous prime is 261215077. The next prime is 261215113. The reversal of 261215081 is 180512162.

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

It is a cyclic number.

It is not a de Polignac number, because 261215081 - 2² = 261215077 is a prime.

It is a super-2 number, since 2×261215081² = 136466637083673122, which contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 261215081.

It is not an unprimeable number, because it can be changed into a prime (261215011) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 62000 + ... + 66078.

It is an arithmetic number, because the mean of its divisors is an integer number (34590240).

Almost surely, 2^261215081 is an apocalyptic number.

It is an amenable number.

261215081 is a deficient number, since it is larger than the sum of its proper divisors (15506839).

261215081 is a wasteful number, since it uses less digits than its factorization.

261215081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7863.

The product of its (nonzero) digits is 960, while the sum is 26.

The square root of 261215081 is about 16162.1496404408. The cubic root of 261215081 is about 639.2431490990.

The spelling of 261215081 in words is "two hundred sixty-one million, two hundred fifteen thousand, eighty-one".