247945 has 8 divisors (see below), whose sum is σ = 315144. Its totient is φ = 186624.

The previous prime is 247943. The next prime is 247957. The reversal of 247945 is 549742.

It can be written as a sum of positive squares in 4 ways, for example, as 138384 + 109561 = 372^2 + 331^2 .

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

It is a 6-Lehmer number, since φ(247945) divides (247945-1)⁶.

It is a cyclic number.

It is not a de Polignac number, because 247945 - 2¹ = 247943 is a prime.

It is a super-2 number, since 2×247945² = 122953446050, which contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 8.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (247943) 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, 1374 + ... + 1543.

It is an arithmetic number, because the mean of its divisors is an integer number (39393).

2²⁴⁷⁹⁴⁵ is an apocalyptic number.

It is an amenable number.

247945 is a deficient number, since it is larger than the sum of its proper divisors (67199).

247945 is a wasteful number, since it uses less digits than its factorization.

247945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2939.

The product of its digits is 10080, while the sum is 31.

The square root of 247945 is about 497.9407595287. The cubic root of 247945 is about 62.8229681900.

The spelling of 247945 in words is "two hundred forty-seven thousand, nine hundred forty-five".