247116721 has 4 divisors (see below), whose sum is σ = 251305200. Its totient is φ = 242928244.

The previous prime is 247116713. The next prime is 247116733. The reversal of 247116721 is 127611742.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 247116721 - 2³ = 247116713 is a prime.

It is a super-2 number, since 2×247116721² = 122133347595583682, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (247113721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2094151 + ... + 2094268.

It is an arithmetic number, because the mean of its divisors is an integer number (62826300).

Almost surely, 2^247116721 is an apocalyptic number.

It is an amenable number.

247116721 is a deficient number, since it is larger than the sum of its proper divisors (4188479).

247116721 is an equidigital number, since it uses as much as digits as its factorization.

247116721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4188478.

The product of its digits is 4704, while the sum is 31.

The square root of 247116721 is about 15719.9465966014. The cubic root of 247116721 is about 627.5293519177.

The spelling of 247116721 in words is "two hundred forty-seven million, one hundred sixteen thousand, seven hundred twenty-one".