261641243 has 8 divisors (see below), whose sum is σ = 263694288. Its totient is φ = 259593984.

The previous prime is 261641179. The next prime is 261641249. The reversal of 261641243 is 342146162.

261641243 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 261641243 - 2⁶ = 261641179 is a prime.

It is a super-2 number, since 2×261641243² = 136912280077170098, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261641249) 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, 138755 + ... + 140627.

It is an arithmetic number, because the mean of its divisors is an integer number (32961786).

Almost surely, 2^261641243 is an apocalyptic number.

261641243 is a deficient number, since it is larger than the sum of its proper divisors (2053045).

261641243 is a wasteful number, since it uses less digits than its factorization.

261641243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2893.

The product of its digits is 6912, while the sum is 29.

The square root of 261641243 is about 16175.3282192356. The cubic root of 261641243 is about 639.5905934654.

The spelling of 261641243 in words is "two hundred sixty-one million, six hundred forty-one thousand, two hundred forty-three".