261717943 has 4 divisors (see below), whose sum is σ = 273097008. Its totient is φ = 250338880.

The previous prime is 261717899. The next prime is 261717961. The reversal of 261717943 is 349717162.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261717943 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 261717896 and 261717905.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261727943) 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, 5689498 + ... + 5689543.

It is an arithmetic number, because the mean of its divisors is an integer number (68274252).

Almost surely, 2^261717943 is an apocalyptic number.

261717943 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

261717943 is a deficient number, since it is larger than the sum of its proper divisors (11379065).

261717943 is a wasteful number, since it uses less digits than its factorization.

261717943 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11379064.

The product of its digits is 63504, while the sum is 40.

The square root of 261717943 is about 16177.6989402078. The cubic root of 261717943 is about 639.6530859138.

The spelling of 261717943 in words is "two hundred sixty-one million, seven hundred seventeen thousand, nine hundred forty-three".